Chapter 1:
Toriel, Papyrus, Sans, Undyne, Alphys, and Asgore walked through ash-coated rocky ridges, a bit dismayed that it wasn't as bright anymore as before. Toriel sighed, "It was very heroic of Frisk to sacrifice themselves for our freedom. I just wish we could still be together." Sans nodded, sympathizing, "Yeah, the kid was great..."
The monsters continued to talk amongst themselves, when suddenly...
"STOP!" A gruff voice shouted. They looked up and saw an orange-furred bipedal creature wielding a whip. Next to him was a human with one red bionic eye. Behind them was a woman who wielded a staff. "What're you doing here?" The orange creature asked, "You are trespassing on Skeletor's domain!" Asgore stepped forward, "Howdy," He said, "I am Asgore, king of monsters. We do not mean harm, but we seek human civilization." The creature considered his options, then said "Follow us."
A ten minute trek later...
They reached a mountain which appeared to be embraced by a three-headed stone snake, each mouth spewing lava. They entered what appeared to be a throne room. The creature on the throne had purple skin and a purple hood covering his face. At his side was a large purple cat with glowing green eyes. He stroked the cat gently. "Oh?" He asked, "Who is this?"
"We found them just out west," The orange creature explained, "They said that they're looking for people." The man who sat on the throne nodded and stood up. The shadow of his hood lifted, showing a skeletal face. He picked up a staff with a small ram skull on the end and walked down to them. "I am Skeletor," He said, "Ruler of Snake Mountain and the Dark Hemisphere, and proper ruler of Eternia."
"And I am Asgore," Asgore replied, "Ruler of monsterkind. Out of mere curiosity, what do you mean 'proper ruler'?" A green creature with a steel red jaw stepped forward, "Oh he means that he wants to take over-" Skeletor blasted him with his staff. "What he meant to say," Skeletor said, "Was that I was overthrown by 'King' Randor. The only reason he wanted the throne was because he wanted the power inside of Castle Grayskull. And if I can't protect it, I'll need to destroy it before he unlocks its secrets."
The monsters seemed to buy this. "We will be happy to assist in any way we can." Asgore said as he shook Skeletor's hand. "Good," He replied, "Now, let's see what you can do."
To Be Continued...
Author's note: Hope you like this! The only Undertale/He-man crossover I found was a Sans V.S. Skeletor, and I hate this wonderful website being plagued with those things.