I have a Mastermind character and a figure that he MM'd the dmg to that has Mystics Team ability. Who takes the Mystics dmg, if anyone? does my mastermind character or the character that attacked him?

Supersenses on the lowerpoint figure is worthless isn't it since he's getting the dmg masterminded to him and not the attack... correct?

Correct. Same reason that Mystics won't activate (see above).