I know that U can use no more than one wildcard TA during each action. But what if U are not performing an action?
For example: U use the Superman Enemy TA to get Outwit, can U ignore stealth with the Ultimates TA while doing so?

You can't do that, as that would be using 2 team abilities at once.

Either they are Superman Enemies, OR they are Ultimates. Not both.

fm

I know that, but the rules say: U can't use more than one TA during an action (in opposit to at once). So I wasn't sure, cause Outwit is no action (even not if generated with Supes Enemy TA).

It's not so much using two TAs during the action, as the fact that you'd need to be able to use both simultaneouly. You coud use the Superman enemy TA and Outwit your opponent's figure. Thing is as soon as you switch the Wildcard over to the Ultimates TA, he ceases to be a Superman Enemy. The figures lose Outwit and per the PAC on Outwit, the Outwitted figures immediately get their power back.

Similarly you could use the Ultimates TA to find your Stealthed opponent, but when you switch over to Superman Enemy to Outwit him, you wouldn't be able to see him any more to do so.