There’s plenty of room for creative hero specials without writing complex and confusing rules.
For example:
A “toxic” hero that counterattacks but sometimes against nearby allies. Nearby allies can also become “toxic”
A “self sacrificing” hero that gives its health and mana to allies in greater need.
A “strategic healer” that only heals the weakest
ally
A “coordinating defender” who marks an enemy and all target there.
A “punishing equalizer” who dispels all buffs and ailments but punishes allies with undispellables and aids allies with undispellable ailments
A “paper minion” with 1 hp and zero attack but that grants a strong buff
Etc
