Ok, so lets say I have a spiderman an ultimates and a batman ally.
Can spiderman use ultimates on hit turn and at then the begining of the opponents turn choose a different ability? Or is it per action?

I think it's a switch per whenever you want but not in the middle of the action

you may change as you wish on ur turn, or when you are targeted on ur opponents turn

Per action. Rule book, page 16:

Wild cards can use a wild card team ability to use only one team ability per action. A wild card begins the game not using any other character’s team ability. A wild card may change the team ability it is using (or choose not to use a team ability) to any team ability possessed by a friendly character when an action is declared by any player but before the action begins.