Need ideas for my crate item

[cougarboy]

Passive gem power? When uses, it takes items, and has a cooldown. puts you in a state where you cannot hurt anyone. but they can't hurt you. once activated, it lasts a certain amount of time. in this state, you cannot pick up items, so you can't look people without taking damage. also, it could be used in pvp, but it takes a total of 9.5 hearts.  so you can only use it at full health.