Okay so I was just glancing over some figures that I had to try and build a team. The figure I wanted to play the most was the Dr. Doom from Classics - the one where his first click is the Mastermind/Invulnerability special power.

My question is, when he's using this power, do they interact with each other? For example if I choose to redirect the damage with Mastermind, will the total damage still be reduced with Invulnerability?

Giving into my laziness and not actually looking at the way the powers are written, I believe that Invulnerability reduces the damage dealt to that character and as no damage would be dealt to that character due to Mastermind, then it never activates.

Nope. In order to reduce the damage with Invuln, he needs to actually be dealt damage. MM specifically says that it activates when the figure would be dealt damage. In other words, you use it before you actually deal the damage to the figure, so it happens before reduction. (Additionally, it say that you pass all of the damage.)

Yeah, Mastermind reads:

So before damage is dealt you can choose between dealing it to Dr. Doom or to someone adjacent. Invulnerability triggers when Doom is dealt damage.

Now, if you mastermind the damage onto someone who has invulnerability, his invulnerability will reduce the damage.

INVULNERABILITY (NON-OPTIONAL) Damage dealt to this character is reduced by 2.

correct