If I mind control GSX Wolverine who is 99 points and has the Four Horseman ATA which brings his total to 100 points do I take feedback damage?

Mind Control:

MIND CONTROL Give this character a power action; it makes a close combat or ranged combat attack (minimum range value 4) as a free action that deals no damage. A successfully hit target becomes friendly to your force. Each target hit may be assignedone action as a free action, immediately after which the target becomes an opposing character again. Deal this character 1 unavoidable damage for each 100 points of the successfully hit targets’ combined point value.

I think the mind controller takes the damage because you factor in the ATA into the point value. But where do the rules say that you do this?

The rules do not say you do this because you do not do this. The point value is what is printed on the base.

It seems counter-intuitive because of how points are scored for KOs. He is worth 100 points if you KO him but only 99 if you mind control him. Good to know with all of the additional elements like the gauntlet and special objects, thanks for keeping me straight!

It's actually a lot simpler to not adjust the point cost, as it comes into play for a variety of different powers, like Mastermind.

You can't use ATAs during a mind control, so you only had the ability to use 99 points worth of stuff during the mind control.

So you're saying, if a character is 99 points or less, you don't take an unavoidable damage for mind control? It was told to me that characters 1-100 points would deal you 1 unavoidable damage, 101-200 would deal 2, and so on and so forth.

You were told wrong
0-99 is 0 points of unavoidable.
100-199 is 1 point of unavoidable.
Etc.

Actually he is worth 99 points. Period.

There may be other stuff attached to him (feats, ATAs, etc) that are worth additional points, but Wolverine will ALWAYS be 99 points.

Good to know, thanks!