(Extreme gore warning, viewer discretion highly advised)

Deutsche left with A-H a week later, he didn't even bother to say goodbye, that's how much the Mandorians hurt him.  The brothers realized too late what they did and they couldn't apologize for it, they just hoped they didn't jeopardize their relationship with the German.

For Deutsch, he was still fighting for the brothers but it wasn't like before, this time it was a tactical move to gain their alliance when he takes over the Prussian Empire, because there were no ifs about it, he was going to defeat his father, no matter how high the cost.

The war raged on for almost a century, the Prussian and the now Austria-Hungarian armies were formidable forces and neither wanted to give up.  In the beginning, Prussia had the upper hand thanks to his experience and military power, and for a long time, it looked like he was going to win.  The A-H army wasn't backing down though, what they lacked in experience and power they more than made up for in determination and ferocity, making sure that no Prussian was left alive during battles.

As the war dragged on, a new problem for Prussia appeared, and it took the form of France.  When France heard that Deutsche and A-H were fighting her adversary, she jumped at the chance to help them take him down. 

The tides of war had turned in favor of the Allies and within a span of a few years they have all but decimated the Prussian Forces, forcing Prussia to gather the remainder of his once terrifying army and retreat to his castle, but this would prove to be his last mistake.

The Allies had a secret advantage, Deutsche had lived in that castle his whole childhood and knew all the hidden entrances and secret passageways, so while A-H and France's soldiers preoccupied Prussia's men, he snuck into the castle to find his father.

It didn't take him long to find Prussia waiting for him in the throne room, armed with his sabers.

"Well well, look who came crawling back," Prussia sneered, "did you miss your daddy, Deutsche?"

Deutsche glared at Prussia, "indeed I have Prussia, and I have been waiting for this moment for years."

The young German unsheathed his own pair of sabers, but Prussia looked unimpressed, "now is that any way to treat your father Deutsche, I thought I raised you better this."

"ENOUGH TALK!!!" Deutsche screamed, "I am putting an end to your miserable existence, so fight me you coward!"

Prussia stared at his son without emotion, then he adjusted his hold on his sabers and lept into the air to gain the high ground, the enormous size of the throne room allowing for him to stay airborne.  Deutsche, however, was undeterred by his father's obvious advantage over him, he took up a defensive position and waited for Prussia's move, and when the German king divebombed his son, Deutsche rolled under him and sliced his right-wing.

Prussia yelped and crashed face-first on the hard floor, he was slightly dazed from the impact but quickly shook it off and stood up before Deutsche could strike him while he was down.  Prussia looked down at his limp wing and was shocked at how deep the gash was.

"How does it feel to be grounded Prussia," Deutsche smirked, "now your just like everyone else."

Prussia growled, he hated being compared to others, so now unable to fly, the older German charged the younger German and they locked swords, both determined to kill each other, neither willing to die.

Prussia severely underestimated his son.

Two hours later and the two Germans were still fighting.  Both father and son were seriously injured and at risk of bleeding out if they didn't stop, but it was a risk they were willing to take if it meant one was to die by the other's hand.  

As the two stalked around each other they waited for someone to make the next move, but it was obvious that one of them wasn't going to hold out much longer.  Prussia's injuries were far worse than Deutsche's, his throat was slashed, his left arm was broken, and his right eye and wing were completely severed off.

"G-getting tired, o-old man?" Deutsche rasped, several broken ribs making it hard to talk.

Prussia didn't say anything, he couldn't without choking from his throat injury, he just kept stalking until his legs refused to move anymore.  Eventually, the German king couldn't hold himself up any longer and he collapsed onto his back.  Deutsche smiled and walked over to his father, placing his foot on his chest as a sign of victory.

"At long last, the time has come, I have been waiting for this moment my whole life," Deutsche said, "I finally get my revenge on you dear Vater."  He lowered a saber so this tip was touching Prussia's throat, "so, do you have any last words before I end your wretched life?"

Prussia stared into his son's eyes and let out a labored chuckle, "(cough) oh Deutsche," he said, barely above a whisper, "I am so proud of you mein Sohn, you have become just. Like. Me."

Deutsche glowered at his father, "I am nothing like you."

"But you are (cough) by killing your own father, you-(cough) you're just stooping down to my level."

Deutsche's eyes widened, that was the same thing Mandara told him oh so long ago.  His hold on his saber faltered as he remembered his Mandorian friend's words, was this really the right thing to do, was killing his father really the answer?  Unfortunately, as Deutsche stared down at the man who had tortured him his whole life, he felt his humanity wither and die, and something much darker take its place.

The young German raised his sword over his head, "then so be it, Vater."

Prussia's remaining eye widened in fear at his son's words, but before he could say anything else, Deutsche brought the sword down as hard as he could.

"Deutsche!  Deutsche where are you?!" A-H called out.  He and France had been searching for him for the past half-hour ever since they defeated the last Prussian soldier.

"Deutsche answer us, we can leave now, Prussia's been defeated," France shouted through the castle corridors, but an answer came none.

The two empires were getting scared and were wondering if something happened to the German, that fear grew when they started smelling the metallic odor of blood waft from a particular hallway.  France and A-H exchanged nervous glances and hesitantly followed the smell to a giant room large enough to fit a small village.  As France looked around she spotted something on one side of the room that made her blood freeze, Prussia's severed wing.

"W-what happ-" she started, but A-H said something that stopped her, "Deutsche?"

France turned to where A-H was facing and saw a truly horrendous sight, Deutsche was standing in the middle of the room, staring down at his father's headless body.

At this point, France wished she was blind like A-H so she didn't have to see this, but when she turned to her fellow empire he had an expression of equal terror and disgust as her own.  They turned back to Deutsche and A-H called his name again, the German didn't move, but a quiet laugh could be heard coming from him.

"I'm sorry dear Freund, but Deutsche isn't here anymore, he died along with his father," he said, then slowly turned to the two with a look of pure insanity in his eyes, "my name is German Empire."

(I apologize if this chapter was too much for some people, I can change some things if need be.)