Crossgen TA says:

CrossGen When this character takes damage from an attack, it deals 1 damage to the attacker. This damage may not be evaded or reduced.

I would assume that you can't use Mastermind to avoid damage from crossgen and consequently mystics but have heard otherwise recently. Anybody have an official ruling on this?

An exerpt from DrGandalf:
"Mystic retaliation is not an attack, and the use of Mastermind does not constitute an "evasion" by the definitions stated in the glossary. Therefore, if a figure with the Mastermind power was dealt damage from the Mystic/Crossgen team ability, they would be able to shift that damage onto an adjacent, friendly, lower point figure. However, that figure would still not be allowed to use their damage reduction or evasion superpowers to lessen the damage (per the PAC's description of the Mystic/Crossgen team ability.)"

Mystic/Crossgen retaliation can be masterminded.

Thanks Maestro.