So Ginnoken requested a story about Skeletron Prime, so I changed it up a bit. Here goes:
Once there was Skeletron. That was all there was. Skeletron was the most revered and most famous of the primordial bosses. Then came a new competitor. The new age, 1.1 had just dawned and the tides were turning. The old bosses knew that their time may have come for a new leader. The Wall of Flesh. It cam through the world, releasing the ancient spirits. The old bosses had known about these; they had always suspected the Demon Altars held monumental evil. The world was torn apart. The new biomes, Hallow, the extended Corruption. They all meant nothing good. Angry, the old bosses decided to confront the WoF.
Confronting the WoF. That's where we left off. When the WoF killed each of the pre-hardmode bosses, as he was much more powerful than the others, a strange phenomenon happened. The souls of the elder bosses, the ones that had once posed such a challenge, were now just vapor, like these. The bosses swirled up and up, fading into the night sky. Encouraged at the victory, the WoF was now the supreme leader. But then they came back. The eldest of the champions. In stronger forces than ever before. Aided by a force, unknown but known at the same time, so evil that the Eater of Worlds himself, the toughest of them all, cowered before his shadow. Kathooloo. (Take that, Jetstream.) Falling into the category of necessary evil, the elders had traveled to his lair in exchange for armor, the toughest ever seen. Having technology beyond comprehension, Kathooloo (huehue) cloned the Eye of Kathooloo. The monsters were connected by a vast string of poisonous flesh, taken from the breast of Kathooloo himself. The Eater of Worlds was fashioned an army of metal drones to do his bidding. And Skeletron, the king of the early bosses was fashioned a majestic armor of Titanium and a spiked collar that allowed him to spin with ferocious intent. His weak bone arms were replaced with beautifully crafted laser shooters, cannons, saws, and clamps. "With these new materials", Prime bellowed, "We shall destroy that puny wall!"