RulingHall of Heroes (rules 1.0–1.4)

Mutant Genesis: How does the newly revealed “Mutant Protectors” work? This card looks awesome, but it is really confusing…

Question

How does the newly revealed “Mutant Protectors” work? This card looks awesome, but it is really confusing us, especially its (defense) label. Mutant Protectors says “Hero Interrupt (defense): When an enemy attacks, put an X-MEN ally into play from your hand. Exhaust it and declare it the defender for this attack.” Does “Defend, Defense” bullet #4 make the player’s identity the defender when that player begins resolving a (defense) ability? If so, does bullet 2 prevent Mutant Protectors’ second sentence from successfully resolving? If it doesn’t, why not? Does “Defend, Defense” bullet #4 make the player’s identity the defender when that player finishes resolving a (defense) ability? If so, does bullet #3 mean this card is not playable in the first place?
Or does the player’s ID end up the defender after all? Does the (defense) label have any effect? Mutant Protectors does not appear to provide an explicit exception to following normal “defense” rules. It only seems to require such an exception because it has the (defense) label, while the label itself doesn’t seem to have any relevant effect in the normal use of the card. We are really puzzled about why it is there in the first place, if in the normal course of events, it is ignored – but in the unusual situation in which the player has already defended the attack, it is able to override Defense rules and make the ally the defender anyways (but without an explicit exception to defense rules allowing such a thing).
Sorry for the rambling, the short version of our questions are: 1. How does playing Mutant Protectors work? At what point, if at all, is the resolving player’s identity the defender? 2. What exactly does it mean to “declare [a character] the defender” for an attack? 3. After playing Mutant Protectors, did I “defend”? Can I trigger “Indomitable”? If my identity took no damage, can I trigger “Unflappable”?

Answer

There are two main considerations for the Mutant Protectors card: The “defense” keyword signals that the player controlling Mutant Protectors is now the defender of the attack. While your ally defends against an attack, “you” are not the one defending. In other words, following an enemy’s attack initiation, you can play Mutant Protectors as a Hero Interrupt to declare yourself as the defender of the attack, and then immediately play an X-Men ally to become the new defender of the attack (who ultimately takes the damage from the attack).

Only one character can be the defender of an attack (the X-Men ally in this case), so your identity would not be considered the defender of the attack, and you could not resolve Indomitable or Unflappable in response to the defense.

-Alex