Riot, have you guys considered creating a champion who doesn't use HP?

Something that doesn't use a red bar to determine how close it is to death.

Maybe something like how Mordekaiser (in the lore) has an immortal body, but has to protect his bones or he will die.

Maybe a champion who doesn't take damage normally, but is instead knocked back by any damage he takes.

Maybe something that is completely untargetable, but has to continually accomplish something to prevent their own death (a mana cost for existing, with ways for both the champion to restore their mana and their enemies to burn it off).