It would be one of either the Large Body, the Flantastic Seven, or the Darkling for me. The Darkling seems to be like what happens to a Keyblade wielder. The Flantastic Seven Heartless seems like a cool and fun kind of species with how their mini games are. The Large Body is a round brawler who seems to use its own round body in comical ways.
What’s your favorite thing about both?
Other than the fact that 7 year old me couldn’t beat either of them for the life of me?
Honestly I thought phantom had the coolest mechanics as a kid, and would quite literally be invincible to anyone who wasn’t an expert magic user. And really, Invisibles just feel like cooler, stronger, sword-wielding neoshadows. They got a super cool aesthetic going on.