I'm just not quite sure how they work, the way I've been using them is you can only pick ONE an action...is this correct? For instance, say if:

Hawk goes to use charge on Hellboy, can I use KC team ability to roll for him coming in, and then if I get hit, declare Mystics?

It seems like people on here play them where you can change whenever, which of course would be better for my LSH army .

One TA per action, but a new TA can be picked for every single action in the game.

This becomes important when you have FF members and Wildcarders. The Wildcarders can get healed when an FF member gets KO'd even though the Wildcarder isn't even involved in the action.

Since the Charge is 1 action split into 2 parts (Move, then Attack), you can't select KC to try to stop the move, then Mystic to do retal. Its one or the other this time.

You can switch once per full action. On your own turn you can switch as much as you want as free actions (IE: The WC takes a free action to instigate the change).

So you can switch to BatsAlly when your enemy is saying it wants a ranged attack on you. Now that you're in stealth that action is illegal, so they declare a charge. Now you can switch your TA to either KC to try to stop the move, or to Mystic to give some hurt back (but not both).

Switching your wildcard's affiliation does not require a free action---it simply happens, much like the use of Probability Control. And you're not limited to only using it during actions, or to waiting for an action to begin before you can switch; the limitation is that you cannot use more than one ability during an action, not that an action is required to use your wildcard ability.

The answer is still right about KC/Mystics, but this issue often needs clarifying.