From the HoG FAQ:

The Enemy Within
Plot Twist, 2
Ongoing: At the start of the recovery phase, if three or more Doom characters were put into your KO'd pile from play this turn, you may put one of those cards from your KO'd pile into your front row exhausted. If you do, remove from the game all other character cards in your KO'd pile that were put there from play this turn.

FAQ text: At the start of the recovery phase, count the number of characters put into your KO'd pile this turn that had the Doom affiliation as they left play, whether or not they are still in your KO’d pile. You can put one of them into your front row only if it has remained in your KO’d pile since being put there from play. You can do so even with a character card that entered your KO’d pile in response to this triggered effect. You don’t count cards put into your KO’d pile from your resource row this turn, nor can you return one to play, but you must remove them if you do return a card.

In summary, I don't agree with their justification.

For example, let's say I have a Hercules in my row on turn 2, I have Avengers and Doom crossed over, and I replace Herc. He goes into the pile. Now, the LAST part of the FAQ text says that he's considered to have gone from play to my KO'd pile for purposed of removing, but NOT for purposes of being an eligible target for the effect? This doesn't make sense, it can't both come from play and not come from play.

Basically, I don't understand why the heck Herc couldn't go into my front row.

Or maybe this is obvious and I'm just tired.

*shrugs*

I think it's so you can't have a 7 cost character on your side of the field on turn 2 or 3. Just a guess.

I understand the REASON, I just don't see that the card they printed accomplishes that. The way I'm reading the card, you CAN do that, and the FAQ text is flat wrong.

I really hope I'm wrong, cuz otherwise the game just broke.

No, you're reading the card right, they just made the ruling on the card as such that it would disallow those kinds of shenannigans.

Herc wasnt a CHARACTER when he was put in the KO'd pile, he was a CHARACTER CARD thats the differance

Ahhhh, there we go.

*hugs Togorian*

The game's not broken! :D

I though my "just because" answer was pretty good.

yeah, i had to read the cardtext a couple of times.
its those little things that will get you.
i thought that the new errata on Witching Hour went infi, then i realized that, just like its original ruling, once the card changes zones, its not the chosen card anymore