NO POWER:
-No magic/powers/no superhuman feats/crazy weapons.
-everything is realistic (no ray-guns or Iron Man suits,Etc).
LOW-POWER:
-There are some powers but they are not over-the-top.
-Enemies who are not assisted by said powers should be able to have a fair match with those who do.
- Characters given powers should have a lengthy cool-down or preparation time to regain the spell/abilities they expended.
MEDIUM-POWER:
-Every Character should have at least Three abilities.
-A non powered/weaponized character should have a hard time fighting this character type.
-They can use there abilities more frequently but have a big drawback or some balancing device to make sure they are not crazy powerful.
HIGH/ULTRA POWER:
-Almost god-like terms of powers in power.
-No mortal should and will stand a chance in a fight
-Completely absurd amount of power in abilities/weapons
-The character that are almost god-like should be kill-able or else it isn't a fair fight(obviously.)
Ooooh. Colorful.
"-No mortal should and will stand a chance in a fight" No mortal should stand a chance against a Medium-Powered character, to be honest.
Also, I feel like there is this large gap of power between your definition of Medium and High Powered individuals. I'm also pretty sure Ultra is typically labeled above High in most characters I've seen, High being that gap you seem to have jumped over. High-powered characters, for me is the fun zone. Much more creativity in power, more loose, and typically where a lot of characters that participate in these tournaments are at. But, they aren't insanely powered either with every power under the sun and capable of destroying universes with a glance. I think High powered might be able to destroy a planet with some elbow grease involved, but not a typical thing to happen either.