I know a Superman team member can attack a Batman team member in hindering, ignoring the Batman team ability. Let's say it was Taskmaster in the bush... does the Superman team ability override the Stealth power?

Superman (x-ray vision) ignores stealth. So yes he (Superman or any Ally or wildcard) can attack a Stealth character or ignore hindering terrain modifiers.

All Hail Doom!!!!!!!

It's good to be clear on exactly what is really happening with the Superman Ally Ability and the Batman Ally Ability/Stealth.

Here's what's actually happening: the Superman Ally Ability allows you to ignore the effect of hindering terrain when making an attack. This means opponents don't get the +1 defence from hindering terrain. This also means Stealthed enemies can be attacked from range. Why? Because the Stealth power allows the Stealthed fig to "have hindering terrain treated as blocking terrain for the purposes of ranged combat (drawing line of fire)." Since that is an effect of hindering terrain (that is, Stealth will not activate without hindering terrain being present), the Superman Allies may ignore it, since they ignore all hindering terrain effects.

Both previous posters were correct, and did not post anything incorrect, but I just wanted to make sure that the rationale and reasoning behind how the Superman Ally Ability works was fully explained.

NO! WRONG! SupermanAlly does NOT negate or override Stealth. At least, not completely.

"SUPERMAN ALLY: Figures on this team ignore the effects of hindering terrain (including team abilities that grant hindering terrain bonuses) on movement and combat. "

Note the emphasis. There's a reason those words are there - Outwit and Perplex. Those two powers are neither movement nor combat. You can't use SupesAlly to Outwit or Perplex a Stealthed figure. I don't know why this hasn't made it to the FAQ, but trust me it's true.

There is a question regarding Probability Control, and it was last ruled that it's tied close enough to combat to be allowed. But this is under review and may change.

Be careful with this one, people.