Solipsism

"Well, I did create Muscleus to be a hero. I'm sure that he will manage on his own," I said. Sure enough, I watched as one of the villagers came back to tell everyone the news of the invaders. Muscleus wasted no time, taking one of the finest blades in the village, and marching down to the city.

He encountered several obstacles along the way; monsters and highwaymen who decided to attack Muscleus for no apparent reason. Was the other voice behind these attacks? Well, if he was, they weren't very effective. Muscleus reached the city with ease, and managed to earn the right to duel the enemy commander.

"See?" I said. "Look at how heroic he is. The enemy commander agreed to a duel, even though there is no tactical benefit to such a strategy."

"Does that really make him a hero?" asked the other voice. "I'm pretty sure that just means the enemy is seriously inept. You're making this too easy for him."

"I already told you, I had nothing to do with this!" I yelled. "Just... shut up and watch the action." The opposing army led Muscleus into the center of their main camp, forming an arena whose spectators formed the boundaries. Muscleus threw his sword into the ground, opting to defeat the enemy commander with nothing but his bare hands. The enemy commander, on the other hand... drew out a laser rifle?

"Gosh, how did that happen?" said the other voice, as Muscleus was quickly obliterated with a foreign weapon. "I can't believe you gave the villain such a powerful weapon as an artifact."

"I didn't-" There was no point in finishing the sentence. I could do nothing but watch as the reality I had so carefully made began to unravel, now that the hero which served as its pillar had been killed.