Honestly, he's got the motivation to come to Earth (kill gems), he's got the skills (fighting style based around hurting Gems), and he's got the backstory (gave up his homeworld, family, and friends to go around space killing gems for years) to make for a villain building off of the Gems' warmongering and lack of respect for the sanctity of non-gem life. Heck, even their lack of respect for gem-based life. Remember Lapis and all the other neat toys they have that are powered by enslaved gems?