I have a suggestion. How about Songbird.
Any chance in having an Asian champ? Over 100 playable champs and there's 0 representation and no Psylocke(Elizabeth Braddock) don't count. Seems a chance was missed by having Sunspot instead of Sunfire.
Franklin Richardsidea for his sp3:If he has (?) on his combo meter, he can summon any champ in the game to fight on his behalf. That champ then replaces Franklin for the remainder of the fight. The combo meter determines what star level the champion comes into play as. (i.e. if it's a rather low combo, maybe just a 3*. If it's a high combo, maybe a 6*.) As to what character is summoned, it can be any champ (even those you don't own) and could probably be pre-determined in setup, just as Stealth Spidey selects his cartridges.
High Evolutionaryidea:He evolves his teammates: each gains the highest stat among them (i.e. if they have King Groot on the team, all of them gain his HP. If Wasp is on the team, everyone gets her base attack. Same goes for crits, armor, and block proficiency)