Of course, this whole discussion on compatibility really is pending the new PAC in Fantastic Four Starter isn't it. All it takes is a word or two difference and many of the combos discussed here change.

As for the INv/Mastermind rule, I wouldn't be surprised to see it change so that damage could be reduced, then MMed. Why? Well for one, it would make those figures way better and there aren't that many with the combo. Also I cite the Chief as a possible signal for a change.

Chiefs SP:STRATEGIST: The Chief can use Perplex and Mastermind (he can deal the damage to a friendly character that has a higher point value if that character shares a keyword with the Chief); damage transfered using Strategist may not later be dealt to the Chief.

Why would the whole addendum for not being able to have it re-dealt to Chief even be there if there weren't going to be a way to reduce damage then shift it off again. Chief has a Scientist keyword like Doom, could you imagine Seth, having created the FF set soon after Crisis, realizes that Doom's SP would allow reduction then MM, which someone points out could create a loop with Chief where if they were adjacent, all damage could be filtered back and forth until it was reduced to 0.

Sure it's a conspiracy theory, but ya never know what the new PAC has in store.....

Because you could in theory juggle the damage back and forth ad infinitum?
I think it is one of those "let's put it in there to avoid confusion" moves, like specifying Gorgon cannot use objects when he uses Quake...

Its also helps when being psy. blasted or exploit weakness used against you. you can avoid the attack as opposed to reducing damage. i made this a lot harder than it had to be.

What he said to avoid an infinite loop where someone keeps transferring the damage between 2 characters with MM &/or an SP that allows the use of Mastermind. Watching someone's infinite loop is like watching paint dry, boring & not fun at all.

Regular MM has to be to a lower point figure, so you can't loop back to the original target. Chief can MM to a higher point figure which could allow regular MM to push back down to Chief creating a loop. As folks have said, it could just be loop-prevention wording.

But wouldn't any judge worth their salt just watch the first 3 seconds of a loop, go "Ok, very funny, now pick something"

They would, but could get reported. As bad as it is to do something like looping the damage, it's still legal. Telling a player he's doing something wrong when he's not can get a judge into trouble. I'm sure in that instance, WK would shrug it off when the report comes in, but it's better to avoid the reporting altogether by putting in the C.Y.A. clause in the power's description.

Yes to all!

Not yes to all. Invulnerability and Mastermind can't be used in the same action. Super Senses and Invulnerability can be used in the same action as well as Charge and Flurry.

I have NEVER, EVER seen a judge interject themselves into a match to stop an infinite combo (especially in M:TG where this is more prevalent). In HC, because victory is dependent more on KO victory points only opposed to KO + Surviving victory points, a player worth his salt would not try to stall out the game by creating an infinite loop because it would basically kill the clock & earn that player a warning for stalling plus it would affect that player's chances of winning the round if that player does not get to take his turn.