Steven Universe has gotten into his share of misadventures before. Life's like that when you're a crystal gem. He knows this and couldn't be happier with the fact. He loves his adventures and he gets to save people while having them; he's a hero. However, even he can't deny he causes most of the problems he ends up having to fix. With that said he swears his newest debacle isn't his fault in any possible way.
You see, Steven has been torn through space and time to some colorful world with talking horses and magic everywhere. It's honestly not that bad in his opinion, and his newest friend is a dragon, but he needs to get home. Thankfully a strange, fury man tells him he can do just that- Steven just has to slay an ancient dragon first; one that has eaten over five-hundred crystal gems in the past...he's got this.
The First Steven Universe/MLP:FiM Crossover I am aware of.