A compiled list of unique champ possibilities

Riot has quite the diversity of champion character qualities. We have earth, fire, wind, water, ice, sound, wolves, fish, trees, samurai, ninjas, mages, monks, all sorts of aliens (void beings), etc. To be honest there doesn't seem to be a whole lot left that can be unique. So why not make a list of possibilities that would still fit into runeterra but also not feel similar to another champ. Below are a few of my ideas.

1st idea: Famous wrestling brothers. Their ult is tag team and they can swap out and each have their own moves and health bars. If 1 goes down the other jumps in.

2nd idea: Cliche super hero. Someone who came upon some powers and decided to help people but now he's off chasing a villain in the league. (Why hasn't this been done yet?)

3rd idea: A spy. He can disguise himself as other units including jungle creeps and gain their auto attack animation and damage but not their abilities.