I did, literally just finished writing it.

"Did you know it's been 10 years, to the day, that some braggart charged through those doors and challenged me to a duel?"
"Can you not remind me of that?" I shuddered at the memory. It was possibly the most embarrassing next few minutes of my life as the Dark Lord, who later introduced himself as Warren, trounced me at swordplay.
"But you were so serious, with such grandeur." he teased. "Standing there, all righteous and proclaim-y."
"Can you not?" I sank into my chair, trying to sink into my chair to escape.
"Oh, I had a moment of concern, but then you struck that silly pose. Poor Marcus."
"You know I prefer Mark." I grumbled, trying to interrupt but Warren carried on as if I never spoke.
"Confident tournament winner, head full of praise and prophecy. You believed so fervently you could take me on and win." I could feel my cheeks burning. Ten years on, and he still knew exactly how to get this reaction from me. "How many times did you lose your sword? I lost count."
"Can. You. Not." I hissed at him. I had trained and fought in tournaments for five years before emerging victorious in the 'Grand Chosen One Tourney'. I was the greatest swordsman in the land. I was praised for my skill. A prophecy was revealed. I was promised riches and rewards once I had defeated the Dark Lord, the leader of a neighbouring hostile territory we had been at war with for generations. Sent on my way with newly forged equipment and a sense of purpose, of completion to my life. Finally, I could accomplish my dream.
The problems? Where to begin? I was sixteen. I was naive. The tournament swordplay was about style and showmanship. Entertainment for the crowd. Flashy moves and countermoves, studied and learned to perfection. Moves designed to mark your opponent, not kill. I was hopelessly outmatched.
"But then you got frustrated." Warren laughed. "Soon, you got angry." He stopped laughing. His voice softened. "You stopped thinking about your 'swordplay.' And that was when you actually became dangerous." I blinked. He'd not said that to me before.
"I'm sorry, what?" I turned my head and looked at Warren. Gone was the teasing, he had an almost kind expression on his face.
"It's true. Once you stopped holding to those forms, you actually showed some natural talent for proper swordplay." I studied his face, but there was no trace of mockery of any kind. "After a few minutes, incidentally the longest time you'd kept hold of your sword," Oh, there was the mockery. "I decided that I'd take you in and train you properly."
"Gee, thanks." I muttered dryly. In truth I was glad he had done so. Over the years it took him a long time to un-train me, as it were, of all the memorised form and movements. During this period he not only mentored me in swordplay, but I taught a lot of his governance methods and ideology as well.

It took a few months when he did take me in, but I soon realised that the 'Dark Lord' was anything but evil. Yes, he ruled a territory hostile to my homeland. But that was because we were trying to attack them. It became clear this was the case when I witnessed such an attack a year in. I groaned inwardly when I watched forces from my homeland 'fight' tournament style against the properly trained infantry. I was amazed when there were minimal casualties, I expected a rout. I learnt why, when I queried Warren about it.
"It's simple, Mark." Warren waved languidly towards a map. "It's a war, yes, but one with minimal effort and loss. I've tried for peace but your king adamantly refuses. So this is the result." Looking at the map, there was a clear zone of 'Battle Territory'. Beside it was a list of locations. In this zone, some small fortresses had been built, designed to draw the attention of my homeland. Each of these seemed to have a schedule of being 'won' and 'lost'.
"What is this?" I pointed to the other end of the map, the opposite side of the territory from my homeland.
"That, Mark, is where the real fighting is." Warren's tone was serious. "Creatures come from that direction. Not organised, but of malice and hunger. They seek food, and we cannot let them pass. They eat anything. Anyone." I shivered at his words. "The front against your homeland is where the soldiers go on rotation, for a rest."

After this my combat training came in earnest. Warren wasn't always the person teaching me, but we sparred often so he could measure how well I was doing. Once proclaimed ready enough, I traveled with Warren on his twice a year visit to the creature front, where I felt the true fear of fighting for my life. There was no finesse here. No showmanship. The creatures didn't care how fancy your footwork looked, how stylish your sword moved. It was kill as quick as possible.

The years passed this way. I became proficient in swordplay. I discovered a people who were happy with their ruler, people who were strong in craftsmanship and industry. Their strength came from a history of fighting these creatures. I once question why Warren simply didn't take over my homeland, it was so much smaller and would be an easy fight.
"The culture." Warren shrugged. "It is alive with such a unique and vibrant culture, to take this away or try to integrate it would be a tragedy. It's important to keep it safe."

"Hey! You with me?" Warren's voice pierced my thoughts.
"Oh, sorry. Was just remembering the early days." I glanced around. "I actually thought you were evil back then."
"And now?"
"You're a good man. You rule well, you have the support of your people. Some things you do for a greater good rather than your own gain, despite it being the harder path. I respect you, and your beliefs." It was the truth. Warren had shown his worth over the years. However, one thing nagged at me, one thing he had never answered. "Why have you invested so much into me?"
"It's time you fulfilled the prophecy." Warren replied, smiling. I went cold. I had forgotten all about that. I stared at him, at a loss. I couldn't kill him. Not now. Not after everything he'd taught me. I realised then I loved him like a father.
"No." Not a chance. I would not do this.
"Excuse me?"
"I am not going to kill you." My voice was steel. Determined.
"What are you talking about?" Warren looked very confused.
"The prophecy, where I defeat the Dark Lord. I refuse." I remained steadfast. Prophecy or not. This was my choice.
I wasn't ready for what happened next. Warren burst into laughter, howling as he hammered the table between us. He thought this was funny? I glared at him. He laughed harder, and longer. I was irritated.
"What, exactly, is so funny to you?" I growled. Warren held up his hand, trying to calm himself. After a few moments, he managed to speak through barely contained laughter.
"Do you remember your first words to me, those ten years ago?"
"Yes." I was still grumbling. "I had been sent here to end the Dark Lord, as per the prophecy."
"Wrong." Warren looked at me intently. "Try again." Wrong? I closed my eyes, thought back to that fateful day.
"I am Marcus." The words came from a distant memory, when I had practised my speech over and over. "I have come to fulfill the prophecy of my people, where I will end the Dark Lord's reign over this territory. Prepare to meet your demise!"
"Yes, Marcus. Where you would end the Dark Lord's reign." I opened my eyes, Warren was studying me. "I haven't been training my assassin, I've been training my successor."

... Oh.

Note to self, write for this one after you wake up in the morning.