(Third POV)

Blood flew from (Y/N)'s head, signaling the death of the man as his torso fell to the ground of the wooden stage. The crowd cheered except for a small group of people, who finally noticed the unwelcome guests. Ariel and Lucy walked towards the group, most likely noticing their presence. Rias has to order Koneko to hold Issei back, despite what she said, she wanted nothing more than to tear these two nobles apart.

"I don't regret what I've done." Ariel's words did nothing but piss everyone off more. "(Y/N)'s existence was a stain on the sheet I call my history, so I had to dispose of him so my oldest daughter could take the throne."

"Don't you dare call (Y/N) a stain, he was someone who wanted to do nothing but protect everyone!" Rias was beyond pissed upon seeing this woman, who was quite possibly worse than Riser. "He would have handed the throne to your pathetic daughter without a moment's hesitation!"

"Even so, he's a part of my past I would much rather forget." Ariel remained perfectly emotionless as she spoke. "I demand that all of you leave, you're al on my husband's territory."

"You killed MY son, so I'm not leaving until I get revenge!" Asger pointed one of his shotguns at Ariel, who didn't even flinch, while Asger struggled to pull the trigger.

"Go ahead and do it, prove to these people that humans are nothing more than scum." Ariel invited Asger to kill her, but Asger began crying at the realization that he couldn't do it. "Of course you couldn't do it. You're a weak man, Ann even weaker father."

With a snap of her fingers, Ariel ordered several fish knights to surround the group. Their swords were all pointed at them, and in response to his, everyone except for Natalia and Asia got into combat stances. Ariel bore a wicked grin on her face before she gave the order to kill all of them. All the knights raised their swords, but not in sync, and the nights managed to leave a scar on Akeno's cheek, but before anything else could be done, a blood curdling scream could be heard from the stage. Everyone turned their attention to see the source of the scream to see the executioner was dead on the stage, with his chest cavity crushed with immense force. However, the corpse of (Y/N) was nowhere to be found.

"Excuse me...I told you if you harm them...I will kill everyone on this island..." (Y/N) emerged from the crowd with a bloodied shirt and a wobble to his step. "Don't make me stay true to my word..."

"(Y/N)'s alive?!" Koneko seemed genuinely shocked by this, but given how no one can see (Y/N)'s eyes, no one can be sure.

"Impossible, we saw his head get blown out by that gun..." Rias was in clear shock, Asia certain didn't heal him, even if she could heal the dead. "This is too good to be true."

"Guards, what is the meaning of this?" Ariel demanded as the fish knights looked at (Y/N) in horror. "I told you to execute the boy, so do your jobs!"

In response to this, all the soldiers got over their shared shock and surrounded (Y/N), who didn't even react to the sudden maneuver. In complete sync, the knights stabbed random parts of (Y/N)'s body, making movement impossible for the boy as one knight adjusted his sword carefully so his swing won't hit his allies. Some of the blades managed to cut off (Y/N)'s right arm clean off. Despite the multiple blades going through his body, (Y/N) didn't even flinch, not did he cry or yell. He just stood there and took every single stab before the last knight finally cut off the boy's head. (Y/N)'s head flew into the air before landing in the ground next to a member of the crowd.

"Now that he's dead, kill these intruders!" Ariel ordered, causing all of the knights to go back to the small group of people, but despite having no support, (Y/N)'s body didn't fall.

"Right away mam!" All the knights said in sync, but then one of the knights realized that his sword was missing. "Hey, did you see my sword?"

Before anyone could answer his question, the sword in question plunged itself into the backs of one of the knight's backs. Holding onto the sword was the bloodied right arm of (Y/N), somehow moving on it's own. At the same time, (Y/N) head launched itself from the ground and planted itself back on it's owner's shoulders. The skin and muscles began attaching themselves back to the base of the neck. Once the neck was back in place, scales that looked to be made of jade covered the once injured part like the scales fused with his skin. (Y/N) walked towards the corpse of the fallen soldier and put his arm back together the same way with the same kind of scales now covering his entire right arm.

"I told you, I'll become the monster to end all monsters if it means protecting everyone." (Y/N) moved his wet hair from his face by pulling it back, revealing that his once (e/c) irises were now a glowing jade color.

"Kill him already!" Ariel demanded as soldiers turned around once more to face (Y/N). "Make sure he stays dead!"

"I recommend all those who wish to live please leave, I'd prefer not to kill any innocents, but I will if I have to."

(Your POV)

How am I still alive?

I reached into my pockets and pulled out the brass knuckles Rias gave me, since Genbu isn't on me and a much better weapon than nothing. The first knight came at me and stabbed his sword into my leg, so I punched him using my scaled arm. I punched downwards and I realized I have much more strength in my scales arm compared to my uninsured parts. I pulled the sword out of my leg and watched as it regenerated with jade scales covering it instead of flesh. I roundhouse kicked the next two knights, sending them through a nearby building. I quickly realized that every time I regenerate, the stronger I become, but it only works when I'm severely injured.

"Rias, do you have any idea as to what's going on?" My father asked as I uppercut another one of the knights, sending him into the air. "This doesn't look like a selkie's ability."

"I think I know what's going on." Natalia explained as swords plunged themselves into my back, but I turned around and kicked the knights who stabbed me. "Huitzilopochtli is a warrior god, so he has a blessing. I heard stories that when Huitzilopochtli finds a warrior interesting, he will grant him the ability to fight for thousands of years without tiring the ability to regenerate with a body harder than the strongest metals. So basically, this blessing grants him the ability to heal from any injury, enhances his body when he heals, as well as makes him harder to cut or injure."

"Great, So now (Y/N)'s ACTUALLY immortal!" Issei was in shock of the explanation, but as was I.

If Huitzilopochtli granted me this power, I will not let him down.

One of the soldiers tried piercing my head with his sword, so I felt pity for him and allowed him to try, but to his horror, the sword was stopped like it just tried to cut a wall. I moved my hair out of the way to reveal jade scales covered. The knight stumbled back a bit.

"Yeah...you can't cut me anymore, sorry."

I punched the knight in the stomach, sending him through a nearby building before a volley of arrows hit me dead on, but not a single one pierced my body because of the scales.

"Lady Rias, Lord Issei, from this day forward, I am no longer the ultimate shield..."

"Then what are you?" Rias asked as I reeled my fist back and faced the archers.

"The Ultimate Immortal."

I used two charges from the knuckles to send myself forward, the pressure of the wind emitted from my body was immense, but it got the job done and closed the distance between the archers and I. I directed all of my rage at the archers, allowing me to punch every single one while their useless arrows bounced off my now invincible body. Some had the courage to try and cut me using their shortswords but it was useless. Still, I respected their courage and kicked them away instead of using my brass knuckles, which I'm gonna call Kazekami from now on. My rampage was unstoppable, many horse mounted warriors tried piercing me with their spears, but the spears shattered upon impact while I jumped into the air. I raised my fists and prepared to expend three charges. I slammed my fists into the ground in the middle of the cavalry, causing a massive tornado to appear for a couple seconds. The more I fought, the more tenacious I became. I didn't have a worthy fight until someone wielding a greatsword managed to cut me in half, but I regenerated almost instantly and managed to knock the man away. However unlike the rest of the men I fought, this guy managed to get back up after I managed to blow him through a building, all while the tornado finally disappeared.

"You're pretty good for a runt, but I'm better." The swordsman dashed at me with his sword pulled back, and given how he managed to cut me before, I came up with a theory.

I raised my arms into a defensive position and let the man cut my arms in half once again, but my torso was fine. The man was clearly confused by this, so I kicked myself away from him with a flip. My arms regenerated once, while my torso regenerated twice. So in other words, the enhancement buff stacks depending on how damaged I am. While the man was focused on me, I used my arms to deliver a punch in the back, making him think that someone was attacking him from behind. He turned around to confront this nonexistent threat while I closed the distance between with my enhanced leg before kicking him in the head. However, he managed to catch my kick and sent me into the wall of a nearby building as my arms finally came back to me.

"Dad, can you hand me those guns?" I asked as I put the brass knuckles in my pockets. "I think I may need them."

"Oh, sure." My father agreed as I jumped out of the wall and took the guns from his hands.

I charged out to the man, who smiled broadly and prepared his sword. The moment he swung, I jumped into the air and began unleashing the rounds into his back, catching him off guard because he expected a close quarters fight despite me wielding a pair of shotguns. While he was injured, I landed directly on his back and forced him down. To ensure he stays down, I shot him in both legs as more knights suddenly came rushing in, but once they saw the amount of bodies, they were shocked.

"I have the destructive power of house Gremory, the boosting power is the Welsh Dragon, and the tenacity of humanity." I pointed my guns at the mortified knights. "Unlike all of you, I have no limits, so come at me. I have all the time in the world."

In response to hearing my words, all of the knights ran away out of fear,and I turned my attention to Ariel and Nancy, who were looking at me in horror. Every step I took made their faces lose more and more color before I finally stopped directly in front of them. They tried running away, but Nancy grabbed a pair of swords and stopped them. To be honest, I have no idea what Nancy's deal is, nor do I care.

"Ariel, Lucy, Nancy, if you three order anything that comes even close to anyone I care about, I will tear your empire to the ground." I threatened, 100% meaning what I said.

After my little threat, all three girls ran away, out of fear, but Nancy's was more like out of joy. I have a feeling I'll never see any of those girls again, so I turned my attention to my friends, who were apparently watching the whole thing. As I walked towards them, for some reason, all of them tackled me into a hug and I was knocked onto the ground. Asia and Rias were crying, Akeno was hiding her tears, Koneko was clinging to me for dear life, Issei was confused but still joined in, Kiba just did one of those bro hug things, and my father just downright tackled me. As for Natalia, she was taking a picture.

"(Y/N), don't worry us like that ever again!" Rias ordered with tears still coming from her eyes. "We thought you died!"

"I did too." I honestly thought I did die as well, and this did not help the girls relax at all.

"Please just call us next time!" Issei demanded, but then he remembered I left my phone back at home. "Okay, from now on, how about you just NOT follow seal girls into the water. Speaking of which, who were they?"

"The woman was my mother Ariel, and those were her daughters Lucy and Nancy." I answered as I began stroking both Rias and Asia's hair to help them calm down. "When she came back to the ocean, she got married almost instantly."

"What a bitch." Issei realized that she was my mother and my father's ex-wife. "In a good way!"

"No, we agree, she's not exactly good wife material." My father agreed as everyone finally let go and my skin went back to normal. "Hey, (Y/N) doesn't have scales anymore! Is that a good thing or bad thing?"

"I think the scales and buffs are temporary." I have my honest opinion before looking down at my clothes to see them in tatters, except for my parka, which looked different now.

"I say we head home, (Y/N) has school tomorrow and I'm sure these people want us off their island right now." Natalia mentioned the obvious, so we agreed.

I took the time to examine my parka, which was now pure white and looked more like it was made from the skin of an actual seal. It looked brand new, don't tell me Nancy had something to do with this, did she? My selkie's coat was still the same size, but now my modifications were nowhere to be found. I still had it wrapped around my waist as I followed everyone to a fishing boat. I took a seat on a nearby chair while everyone else sat closeby, with Rias sitting right next to me on another chair.

"I'm sorry I worried you." I apologized as the storm began to calm down and we left the island. "I know you worry about me to death, but I still went with them."

"Why did you come here anyways, were they forcing you to go with them?" Rias asked as neither of us really looked at each other because of the awkward atmosphere.

"Considering they used swords to threaten me, I would guess so." I answered with a dry laugh. "You know, right before my execution, I honestly thought I was going to die for real. So I took time to reflect on all the time I've spent with you guys, and I just wanted to say; thank you."

"For rescuing you?" Rias asked to make sure she knew why I was thanking her, and I shook my head to signal that's not what I'm talking about. "Then what for?"

"For keeping someone like me around." I answered in a slightly embarrassed tone, making Rias giggle a bit. "Please don't laugh when I pour my heart out, it makes me feel embarrassed."

"Well excuse me for finding you cute." Rias teased me a bit more, she was clearly spending way too much time with Akeno lately. "Infact, I should be the one thanking you for joining my peerage, even if you aren't in it now."

"Still, if I never met you guys, I would probably still be alone and end up bearing a grudge against my father for being missing after all those years." I continued being honest since the two of us appeared to be having a heartfelt conversation.

"I guess we both owe each other something." Rias suddenly got up from her chair and sat on my lap, then she hugged me for whatever reason. "For worrying me so much, we're going to stay like this until we get back."

"Very well then." I accepted my fate with a light smile and hugged Rias back. "By the way, who's boat is this?"

"Oh yeah, I ran up to some guy and begged for him to give me his boat." My Father answered without a care in the world, taking these moments to take a breather from the events from earlier. "I had to beg for a while, but it was totally worth it."

"For the sake of your dignity, never do that again." Natalia ordered, and my father agreed with a smile. "Still, I never expected for that necklace to give you such a blessing."

"Nor did I." I could feel my eyelids get tired, so I rested my head on Rias' head. "But I'm grateful it did."

I guess this is where I truly belong.

(A/N: HOLY SHIT I JUST WROTE THREE CHAPTERS IN ONE DAY, I FEEL UNSTOPPABLE! By the way, if you wanna get a better idea of how (Y/N)'s powers work, just read Akatsuki no Yona chapter 100, I based his healing factor off of Zeno's, so the two healing abilities are almost exactly the same. Only difference is that (Y/N)'s healing factor speeds up the closer he is to whatever he wants to protect. One other thing, he's going to use this blessing of his as a last resort because he is not going to cut off his own limbs just to get an edge in a fight. All of the girls will be worried sick if he were to do that.