Super Duper Sumos
Shemo - The Fourth Sumoteer
S1 E25:
Shemo, the fourth sumoteer (separated in the first flashback of the first episode) arrives in Generic City bent on destroying Bad Inc. Shemo is tougher than our heroes, stronger, smarter, swifter... and she's a girl. This leads to sibling rivalry, which ends in a lesson well learned. She's a girl. No wait, it's something more along the lines of appreciating another's talents without being threatened or envious or something like that.