So this scenario came up in an event recently: DP rare Red Hulk & AvX Black Panther Vs AvX Emma Frost. She uses outwit to outwit Red Hulk's indomitable. Then, next turn Black Panther's trait allows characters that share a keyword with him (Avengers) to use willpower if they are within four squares. So my question is, can Black Panther give Red Hulk his willpower back after it was outwitted by Emma?

Yes. For two reasons:

1. You didn't outwit willpower. You outwitted Indomitable.

2. Black Panther counts as a different source. So even if you had outwitted willpower the character would still be able to use the one granted by Black Panther.

Yes. She's cancelling one source that grants a power, not preventing that character from ever using the power. Since she countered Red Hulks indom, he can't use the willpower on his dial. But if another source gave him willpower, like Black Panther or Null's Hammer, for instance, he could then use it through that source.

Short answer: Yes. He can use Black Panther's willpower ability.