I did a quick and did not see this out here and guess it comes down to possess vs use argument, but since Cable's special does not use either word, I wasn't sure.

COMING AFTER ALL OF YOU: Cable modifies his attack and damage values by +1 when attacking a character with the Avengers keyword or team ability.

If a wilcard copies the Avengers team ability, does Cable get the +1 to attack?

and if so, can't the wild card character, change the TA he is using on Cable's turn so Cable does not get the +1?

Thanks!

No, they need to possess the team ability. Wild cards wouldn't have to worry unless they also had the keyword.

I guess my confusion is that the Cable power says

COMING AFTER ALL OF YOU: Cable modifies his attack and damage values by +1 when attacking a character with the Avengers keyword or team ability.

From the Rule book:

Wild card team abilities allow a character to use any team ability possessed by any friendly character on the battlefield.

Is with the same as possess?

Yes. And, for the record, this is not even close to the first effect to use such terminology. For example:

Defenders, Ride with Me: Silver Surfer may carry up to two single-base characters regardless of their combat symbols or possessing Battle Fury. When Silver Surfer carries only characters with the Defenders keyword or team ability, modify his speed value by +2.

Silver Surfer would not get the +2 modifier if he carried a wild card copying the Defenders TA.

Cool, Thanks for the help. I trust your judgment on this. It came up in the last AvX and we ended ruling it this way, but wanted to make sure.

"With" should be read as "possessing." In other circumstances it's worded as "using."