Night from the very far place, Zeref is sitting from afar as he watch Natsu with everyone else leaving the guild to return to their own homes. Zeref continue to smile, not minding the place surrounding him is dying. The smile Natsu shows, is something he is glad about to see.

"I'm glad... everything is back to normal... Natsu." Zeref whispered before hearing someone is approaching.

He turned to his side to see Obra with the Lesser Keys of Solomon that Estrela possessed. Obra took it after the battle against Celestial Spirit Magicians. The little figure gave the keys to Zeref which made him smile, glad that the keys are now within his hand.

"These keys are not meant to be used by anyone." Zeref murmured before standing up as Obra climbed to his shoulder.

Zeref took one last time to see Natsu before turning around to leave the place before anyone could sense he's there, especially Mavis whom he can't see nor hear but knew she's around and could be just there.

Zeref continue his walk away from Magnolia. As he do, he can't help but remember the day he had returned back to his empire, Alvarez.

The last time he had seen Natsu was when he rescued the old man, Macarov from his magic and escaped with him. He knew that Natsu in his current state might be able to kill him. He can move and invade Ishgar as he ordered but decided to wait, letting his little brother feel the last moment of his normal life with his friends until the day came when something came wrong.

Within his hand is a book that he cared the most, the book of E.N.D. his little brother's book. The book is like a mirror of Natsu's life and condition which is why even though he won't be there to watch over him, he can still watch over him.

"Natsu's life... is wavering..." Zeref whispered as he feels closely to his book. The feeling of weakness and pain. At first, he had thought that Fairy Tail had ones again faced another formidable foe so he never mind it.

Until the feeling kept still and much more got worst as time goes by.

Zeref can't help but glare, it's been a year ever since. The book still keep emitting weakness, pain added by suffering and breaking.

"I'm going back to Ishgar to check something out." Zeref said before turning to his minister, Yajeel. "Take care of everything while I'm away."

Yajeel bowed down, "As you wish Your Majesty."

Zeref left Alvares ones again with Obra following him. He will find what's truly happening to his little brother.

Arriving to Ishgar, Zeref traveled first to Magnolia where Fairy Tail is located. He found out that everything is peaceful, no conflict is happening between them and anyone else... except the fact that Natsu is missing.

Fairy Tail are deadly worried as they start looking but nothing about him was found. This revelation made Zeref almost lost control over himself and his deadly magic. He walked away from town, knowing already he will not find anything about Natsu. He could still sense it, the pain, suffering and breaking of E.N.D.'s book. If something bad happened to the point of no return, he can never forgive himself.

'Natsu'

Almost another year and even Zeref haven't found anything, much that it frustrated him. He had wondered around maybe the whole Ishgar but found no clues about Natsu. The feeling in his book is getting worst, much that made him even more worried.

"You're Majesty." Obra called, knowing how his emperor is getting impatient which was rare to happen.

Zeref took some time to calm himself before turning to Obra. "Go and find our spy here Obra. Make it fast or else."

"As you wish your Majesty." Obra left as soon as possible to find their spy whom only few know the identity within the empire.

Zeref had kept his wait for Obra to return with the spy he trusted the most.

This spy is actually here to travel around Ishgar and collect information until the fateful day of war. Zeref only had come across this spy rarely, he is actually glad that their spy is doing the job with no complain.

For three days of waiting, Zeref heard a light footstep, finally they arrived.

The first one to show up is Obra who is showing the way. Zeref stood up from his place and turned to meet his trusted spy, the shadow within his Spriggan 12.

"Good job from your work Yua, I'd like to know something within your report." Zeref said coldly.

The shadow of the Spriggan 12 and the spy is none other than Yua, the Hydrologic Magician. The woman kneeled down to her Emperor.

"What is that you wish to know Your Majesty?" Yua asked in loyalty. Zeref gave his question, "I'm looking for a person named Natsu Dragneel, do you have any information about what happened to him?"

Yua was silence, seems gathering everything she know within her head. Zeref is waiting until she responds.

"Zeref-sama I too had heard about his disappearance and made an investigation. Unfortunately I do not know what had truly happened or where he is currently located. All I know is it started from a solo mission that your little brother took. Between the roads of that town, I have found some trace that tells he had fought against powerful magician on his own. The most intruding for me is that there are only few traces of your little brother's magic while the unknown group had many."

Zeref was silence as he absorbed everything he had heard from her. Truth to be told, only Yua knows his Majesty's secret which was his own little brother who's memories about him is sealed. Yua had watch over his struggles to every places without being seen. She must say, his Majesty's little brother is too energetic and truly childish and reckless too.

Yua look to her His Majesty to see him thinking, as if trying to figure out those people's motive when something unexpected happened. The book of END is shining darkly. Zeref stared the book he cared the most and the book that is never opened did open really fast.

Obra and Yua's eyes widen, knowing what it means when the book had been opened. Zeref on the other hand also knew it too as there is a disbelief in his eyes.

"Natsu"

Thanks to the aura that Etherious spread around, Zeref immediately felt its location and immediately run away, heading there with the opened book of END. Yua and Obra didn't waste time to follow their emperor.

Zeref continue to run as much as possible, so fast that almost none could see him passing through. He had never used this much speed before ever since but this is an emergency, his little brother is in danger to the point END had began to awaken which wasn't supposed to happen now.

Zeref arrived near the capital of Fiore but didn't mind as his only focus is his brother. He can feel it, he's getting near to where he is. Arriving there, he saw his little brother, wearing something that he never wears before and standing in top of the water.

His eyes were red and dark aura is surrounding him, the etherious aura. Zeref can't believe this. The last time he had seen Natsu even it was just a short time is strong but the Natsu he now see is different, the weak and easy to break.

"Natsu" The Emperor whispered.

The boy heard him and turned to see him, the one who created him and his brother, Zeref. The boy kept staring, at him before the aura of etherious vanished and eyes turned back to onyx. Natsu closed his eyes before he fall to the river.

"Natsu!" Zeref was about to go and get him when someone went there first.

It was Yua who swim and successfully got Natsu before he drowns. Carrying Natsu, Yua returned back to the surface where Zeref is located and check him as soon as possible.

Yua is not only a spy but also a doctor and born assassin.

They have a clan a long time ago in Alakitasia. They are clan who are raised as strongest assassins in the whole world where everything about them is always unknown. They are also living within the darkness where no one will ever know where they are located. In that family, Yua is trained to become one, learned how to fight, self defense, tactics and many more for their future as an assassin. They enjoyed it even if the training is harsh due to the friendship that been form between them as classmates. Yua is really friendly at that time and love to smile, she would do whatever it takes to survive for everyone, especially to her loving mother who always takes good care of her. That was her life, until the final day came where they will learn how to kill their emotion and become full pledge assassins of their clan.

The final test was to kill their friends with no remorse. That became a shocking announcement to them. Their fathers are there to watch their children from this final test, it is there role to see if their children is ready to inherit the life of assassination or just a failure. Those children who tried to ask or defy their teacher were killed by none other than their own fathers too. That's when everything became clear to them, there is no love and friendship in their very dark world. Afraid of death, most took their weapon and fought their own friends and classmate. Seeing the whole circumstances, Yua can no longer help but wield her knife. It's too painful to kill her own friends whom she too seen as her own family but for her mother who's waiting for her return, she can't hold back and took the battle of survival.

In the end of those suffering test, only five had pass as for the rest had died in their battle. Yua is one of them, eyes already blank as her last kill was her own best friend. The pain is too painful for her, for the age of thirteen. Her own father congratulates her for passing the exam but she never felt happy for that. Their head master will finally give them the acknowledgement as young assassins if they will accomplish the mission that shall be given to them. The mission that Yua and the others four receive is more dreadful. To kill their own mother. Yua who loved her mother so much can't possibly do something like this but the words of the head master is absolute and her own father is pushing her too to kill her mother.

Too much pain and suffering, Yua is ready to take her own life when her own mother stopped her. She gave her last words before pushing the knife she wields to her heart, much as Yua's surprise. That day, her mother died, in her own hands, to protect her, to make her live.

"Zeref-sama" Yua's words made him returned back to reality to listen to her words. "Your little brother is in major condition. It's best if we should give him a proper place to rest and check him ones again."

Zeref nodded before giving his orders, "Bring him somewhere comfortable to rest Yua but not the Capital, the next town."

"As you wish Zeref-sama." Yua carefully took Natsu's unconscious body and run away from the place, leaving Zeref behind.

Zeref turned around to face the clear sky and peaceful tress but for him, all he sees is are dead ones, lifeless ones and mostly the lifeless bodies that will soon piled up whoever hurt his little brother.

'Looks like there will be some rats that needs to be eradicating before my own war begins.'

Soon Zeref went to next town that is next to the Capital. He immediately went to the nearest inn where Yua had brought him. Arriving there, he saw Natsu in bed, still sleeping. He turned to Yua and asked.

"How is Natsu?" Yua took a deep breath before answering, "Weak, malnutrition, suffered greatly and brain damage."

Zeref narrowed his eyes, "Brain damage?"

"I can't really be certain how much brain damage had been inflicted to him but when I checked his eyes, it's too blank. Its either he had gone insane or something is happening to his memories. I'm sorry Zeref-sama, even I can't do anything about it." Yua apologized.

Zeref turned to Natsu in concerned eyes as he slowly held his hands, the hand that he had never held ever since they had been separated for 400 years.

"Will he wake up again?" Zeref asked in whisper. Obra appeared to Yua's hidden cloak who's staring at her. Yua closed her eyes, thinking what to answer before giving an honest answer. "I don't know Zeref-sama. Even though he's an Etherious whom you had successfully revived and created, I cannot tell at all."

Zeref was silence as he absorbed her words. He took a deep breath before waving his hair from his peaceful yet pale face.

"Natsu... be well... please..."

Two weeks ever since and Natsu for the first time woke up. Only Yua faced Natsu when he did, unknown to the boy about someone hiding from the shadow and that was Zeref with Obra from afar, watching him.

"You don't know your name?" Yua asked gently to the boy who's totally pale and emotionless.

It took a minute for Natsu to shake his head, telling he doesn't know his name at all. Yua mentally became serious as she sensed something off about him. She knew he's a magician but... she doesn't feel any magic around him at all.

Zeref felt the strangeness too from where he's hiding. He gave a deep thought about it. The power of Etherious had awakened within him but will never take away his ability to use magic... unless Natsu not only got amnesia but also lost his magic.

Yua continue to ask question and in the end found nothing. Not liking to force him, Yua decide to have him rest after filling him food that is good for him to take. Natsu nodded and sleep ones again. Seeing he's completely in deep sleep, Yua turned to the hidden place where Zeref came out from his hiding place.

Zeref's eyes shows concern over his little brother. He turned to Yua who is only in silence. He knew that something like this, even Yua can't do anything about it. He wanted to stay by his side, take care of him and make sure he would remember everything but...

"Yua" He called which took her attention. He continued in whisper, "I'm leaving my brother to you. Do what you can to recover his memories and magic too."

Yua studied him for a moment, as if not sure if she should comply or not but never the less, she bowed her head. "As his Majesty's wish."

Zeref nodded before turning around and walked away. Obra followed his master as Yua was left on the room with the sleeping Natsu.

Zeref arrived the empty mountains. He looked on the bright sun shine around the place. That shine reminds him about his little brother, Natsu.

"You did well... thank you for taking good care of Natsu... Yua." Zeref spoke as he turned around to see Yua standing from afar. She only smiled and nodded, "I only did what his Majesty had told me to do."

"At first it is... but in the end, everything became your own desire... am I correct Yua?"

She became silence to that before huffing, "You know me too much Zeref-sama."

"I do... I still remember the promise I had made from you before. Do you still remember Yua?"

She would never forget that day, the day where she had first met him.

It was a clear sky but in the barren wasteland is full of bloods. There are too many human bodies around the place, all killed by not only shape of a blade but also ice that are struck to every part of their bodies but it was more in brain and throat, like someone explode inside of their bodies, wide eyes people that seems died from suffocation and far worst is some of them their internal parts were scattered around the place.

In that bloody and unfortunate place, there are only two person standing in the middle of the bloody ground. One was a woman, covered in blood and wounds from her fight from the large number of people she had killed. Her sword is still socking in blood, breathing tired but can still move more than she could. Her eyes show nothing but emptiness and coldness, like she no longer have an emotion of her own. The other one is man was Zeref himself.

The dead people are actually the soldiers of Alvarez whom they protected the emperor from her but in the end just perished.

Zeref is amused, totally amused. Yua can see that but didn't mind at all. She raised her blade and pointed it to the Emperor of Alvarez, she shows no fear at all.

"You, why do you suddenly attack us on your own?" Zeref asked in amusement. Yua didn't answer, all in focus of her own target. Zeref continued, "From what I heard, a clan of Yamiro, the assassins would act within the darkness, not like what you just did. I'm sure your clan already know about my advancement to your home right?"

Yua didn't speak, instead she dashed forward. For instance, Zeref was able to stop her blade by him only finger which made her eyes widen in surprise.

Zeref continue to smirk as he used his dark magic and pushed her far away and bind her. Yua did what she can to get herself out, even used her magic but nothing seems to be working at all.

Zeref approached her, "It's useless, now you will behave and tell me all you know about your clan."

Sensing no hope, Yua stop her struggle and just sigh, still no fear is showing at all. Zeref stared at her for a moment before demanding answer.

"Where is your clan's hiding place?" Yua stayed quiet as she stares at his onyx eyes with no emotions. Zeref was mentally amused and astonished. Who would ever think there is someone who is brave enough to stare at him in eye to eye.

For long studying, Yua can't really read his own thought so she gave up. She answered him, "From here head three kilometers north and head to sixty degree west. You'll see it there."

Zeref was more astonished. To think she would give in so easily.

"Can't tell why I told you?" Yua asked as if she could read him which is actually just a guess. "I desire one thing... death." The word surprise Zeref. She continued, "I want death to come upon me, not in pathetic death but in prideful death. You who is known as the black wizard in Ishgar could give me what I desire."

Zeref studied her, seeing no lies at her eyes even though there are no longer emotions or color.

"So you decide to die in suffering... is that your prideful death?" Zeref asked seriously. Yua didn't answer nor waver from her desire. Seeing that made him smirk, an idea came to mind. Instead of killing her, he offered his hands to her, much as her question. "Follow me."

Yua was silence for a moment before giving her confusing look, "Huh?"

"Follow me and I shall give you your desire." Zeref offered to her. Yua's eyes widen, is he thinking of... taking her? "Why do you not wish to kill me? I killed your men, I pointed my blade to you and still you ask me to become your follower? I don't fear death, it's useless." She said in serious tone as narrowed eyes directed to him.

Zeref shook his head, "I don't desire you following me by force but your own will instead. Follow me and I shall show you a different path with a promise of suffering and dying with pride."

The magic that restraining her vanished. Yua stared at the Emperor of Alvarez and his hand. Too much thinking, too much doubt, still, she's already used being a tool, a tool who knows nothing but to assassinate their target. She no longer mind being used as they always been so she decide to take his hand. The promise of suffering and death, that's what's the most important thing in her life.

Zeref's smirk turned into smile, "My name is Zeref, Zeref Dragneel."

"Yua... Yua Yamiro."

She smiled on that memory, "Yes... I do Zeref-sama. For that reason you gave me this necklace." Yua touched it with gentleness, "The core of what they call immortality. The Life Magic you had put here never made me die, for that reason I had turned to master the forbidden of my magic. If this is destroyed, all the tolls of my magic shall flow to my body and perished."

"Immortality is never been a bliss... but only suffering." Zeref said with a smile. "How long as it been since I gave that to you?"

"Approximately 184 years ago. Not old enough like you."

"Do you wish to be older?"

"Who knows."

Zeref can't help but chuckle. The two never actually expect to be good friends, that is why Zeref trusted Yua the most when comes to personal matters like Natsu while Yua respected Zeref's any decision he made and will make sure to help him in time of needs. Because of that necklace too that Yua became immune to Zeref's deadly magic.

"So what do you think this life now Yua?" Zeref asked as he studies her closely.

Yua closed her eyes to remember her times with Natsu and how much bright Fairy Tail and Sabertooth had become. She opened her eyes with a sad but satisfying smile, pain is mirrored to her eyes.

"Emotions that became rare, things that I never had done, the brightness they produce... The suffering I feel now... is the best Zeref-sama. Who would never think I could feel this way? Truly the best."

To those who will hear it may thought she's already broken to the point of no return but for Zeref it's different. Yua desire to experience things that she had never felt ever since, the life that she may never ever feel or witness. The suffering she feels is the proof that she experienced the best and happiest thing more than anyone else.

"I see... good to hear... Yua." Zeref murmured before turning away. "Natsu already see you as his own mother figure, should I see you the same way as him? We are siblings."

"Please don't Zeref-sama. You remember your parents more than Natsu does. I know they are better parents than me." Yua reasoned.

"Still you're good at taking care of Natsu. Have you ever desire having a family?" Zeref asked when he faced her. Yua suddenly remember her own family, the mother she loves is killed by her own hands, same for her father and her own clan when Zeref-sama ordered her to eliminate the whole clan and she did it with no remorse. She smiled and shook her head, "I don't and never will. I am a born assassin and the only survivor of my clan. My death would end my clan's existence."

Zeref can tell how much she hated her own clan, especially about the time they forced her to kill her beloved mother. He nodded as he accepted her decision, it is her life, she has a right to decide what to do in her life more than anyone else.

Zeref turned to the path where Magnolia, Fairy Tail is located. He smirk, thinking that it's time to do it.

"Yua have you gathered everything I had told you to do?" Zeref asked in deep and serious tone.

Yua took a deep breath before kneeling down before him. "Yes your Majesty. All information in Ishgar including the possible enemies and places are been investigated thoroughly as your spy. I also found the secret basement in Fairy Tail Guild that I believe is the way to where the Fairy Heart is being kept. Unfortunately I cannot go and see it within my own eyes to confirm it. My apologize."

Zeref smirked, "No, knowing the possible place is already enough. I'm sure that if you do Mavis will find you." Yua stayed silence, knowing it's true. "Yua, head back to our country as soon as possible and announce them my coming back and the coming war we shall now about to commence."

Yua nod, "As you wish your Majesty."

Yua stood up and walked out the place in top speed, leaving Zeref alone the place. Obra soon appeared behind the rock, only waiting for him.

Zeref continue to stare at the path where the Fairy Heart and mostly his little brother are located.

"I can't wait for the time you can finally kill me... Natsu."

I do not own Fairy Tail