The "Immortal" Klaw

Q: If you defeat a stage of Klaw and The "Immortal" Klaw is in play, will the next stage still get the +10 hit points?

A: Yes. So long as The "Immortal" Klaw is in play, Klaw will get +10 hit points. When you advance to a new stage of Klaw, you will set his hit points and then add 10 for the side scheme. -(Developer Ruling, Hall of Heroes)

Sonic Boom

Q: If I reveal Sonic Boom, and all my characters are already exhausted, can I still choose the option to exhaust all characters I control?

A: No. If possible, you would have to spend the resources, if all the characters you control are already exhausted. Sonic Boom is a choice, but you must choose an option that you can fulfill. If you cannot fulfill either option, then you must do as much as you can, which typically means discarding one or two different resource icons from your hand. -(Developer Ruling, Hall of Heroes)

Electro

Q: If I defend against Electro with an ally, does his Forced Response still trigger?

A: Villains and minions activate against the player, so Electro’s ability resolves against the player he attacks. If you defend with an ally, he has still attacked you – the player. -(Developer Ruling , Hall of Heroes)

Mark V Armor

Q: If Iron Man has 6 hit point remaining and his Mark V Armor upgrade is discarded from play, is Iron Man defeated?

A: Yes. If an ability that modifies hit points expires or otherwise becomes inactive, the modified hit points revert to the value they would be without the modifier. In this case, Iron Man’s hit points would revert to 0, instantly defeating him. -(Official FAQ, See Rocket Boots)

Vapors of Valtorr

Q: If a Villain is Tough, Stunned, and Confused, can you use Vapors of Valtorr on him to remove the Tough status?

A: No, you cannot stun or confuse an enemy that is already stunned or confused. -(Developer Ruling)