Your FAQ you've provided was talking about the different interaction.

Your FAQ talked about "What if the villain cannot take damage", it didn't talk about GUARD keyword, which make you "cannot target the villain" this FAQ is more accurate.

Under the current rulings, Attacrobatics flops if Black Widow is engaged with a guard minion. I am curious why guard prevents the card from canceling the boost icons and just failing to do the attack/damage to the villain due to guard. Other cards with the same formatting require each sentence to be read in order and you resolve each sentence one by one until it is not possible. In this case, you would discard attacrobatics when a boost is revealed.

Then you would proceed to do as much as possible for the second portion which in this case would be to cancel the boost icons. After the newest ruling on melee regarding sentence by sentence reading this would imply that every card is to be treated in the same way. Melee used to flop if there was a guard minion since both instances of damage occurred at the same time, but the most recent revision change the interaction to deal 3 damage. Then deal 3 more damage to a different enemy which allows you to kill a guard and hit the villain with the second instance.

The reason you can’t trigger Attacrobatics while engaged with a guard minion is because it is an (attack) card. You cannot attack the villain while engaged with a guard minion.

-Caleb

Official Marvel Champions FFG Rulings (pre-RRG 1.5) – Hall of Heroes

Thank you for your understanding.