If someone has stunning blow on and incaps a mystic do they take a feed back?
I know that you dont if you make the fig push but since the feat card takes on the
damage delt and it is an attack and that is what is needed to cause mytic feed back whats the deal?

If the Incapacitating figure chooses to *use* Stunning Blow, then yes you'd take Mystics damage since you are dealing damage to the Mystic. However, remember that Feats are optional and you can choose to *not* use Stunning Blow when you target the Mystic and just do a regular Incapacitate attack, which would not cause retaliation damage.

And of course, they only take the feedback if they actually damage the Mystic. If you had say double shot incap, and tossed all the damage to a non-Mystic, you wouldn't take any damage (even if your incap forced them to take a click of pushing damage).