Im curious about the wild cards team ability, and how often and when they can use it exactly. for instance; when i use charge against a wild card character, and that character has a hypertime team mate and a mystic team mate, can the wild card call hypertime to make me roll to get near and then if i do roll to get adjacent can he then also change its ability to mystic? i was under the impression that you can use 1 team ability per action, which would make my opponent have to choose hypertime or mystic. am i correct on this?

another example of my confusion: if im targeting someone in the bushes who is a wild card with a wild card character of my own, and my opponent calls batman ally which would then make me call ultimates/superman ally on mine could my opponent then change him team ability once he knew what team ability i was using? if i have this whole wild card team thing mixed up, it would be great if any of you could help shed some light on this subject for me

One team ability per action is correct, yes, so he can't use both Hypertime and Mystics against your Charge.

For your other question, no, he can't change the team ability once he's declared he's using one, so once you've declared a range attack against him and he's copied Batman, he can't go back to Mystics.

You are correct that you can use one ability per action. So, in your first example, your opponent would have to choose either hypertime or mystics, but cannot use both.

and when i want to attack his wild card with my wild card and i havent called a team ability yet and he calls batman ally, i can also after that then call ultimates and thats too bad for my opponent?

This is correct as well. After one action is declared then they can't change their team ability.

It can be a good way to trick opponents as well. Say your opponent is in hindering and has both Bat ally and Mystics as copy fodder. If you have a character with charge and some range (and you're in charge range) you can declare an action to shoot them. If they change from mystics to batman to stop your shot then this would make your shot illegal. This also makes them call out batman as their team ability. Knowing this you may now charge them and they cannot change their TA.

one more thing, can a wild card only choose one team ability during my turn to use? like, if someone chooses batman ally can they only use that team ability for the rest of my turn? or can they change it as soon as i attack with someone else?