MIGHT AND MISCHIEF: (non-optional) Thor and Loki uses Battle Fury and can use Exploit Weakness

My question is when they have this power, when they attack do they have to use Exploit Weakness since it says non-optional and if so does that mean they can't Duo attack.

Just want to be sure.

The "can use" makes that part of the power optional - so they can use EW or not, their choice.

No, what the non-optional part means is that you cannot voluntarily cancel the power to get rid of battle fury so that they can make a range attack. You can choose to give them a power action to activate the duo attack (close combat only) or you could give them a close combat action to activate EW.

Maaaaaliccccceee!!!!!!!

yea... really hard to find a way to win with running shot battle fury!