Another Idea for the game is that it could be like The Binding Of Isaac where there are hundreds and hundreds of different items that affect gameplay such as movement, attack type, character appearance, etc. hope this idea is worth putting in, Binding Of Isaac is one of my favourite games
An Ability could be an Ultimate Brofist. The icon onscreen would be and the ability would consist of essentially giant fists raining down from the sky. Of course there would be a counterweight of something like you wouldn't be able to move during the attack or you would also be hurt by the fists as well. The ability might have to have a really long cool down, a limited amount of uses or take form as a collectable off bosses or in chests or something.