I'm curious how his special power works:

AMPUTATION ATTACK...TO SAVE THE UNIVERSE: If a character takes 4 or more damage from Wolverine's attack, modify that character's attack value by -2 for the rest of the game, even if this power is countered or lost.

It says '4 or more damage from his attack'; so how does Flurry affect this? if the target of his Flurry takes 1 damage from the first Flurry attack, then 3 damage from the second Flurry attack, is the 4 total sufficient to qualify for the -2 attack modifier on the target? Or does the 4 damage need to be from one Flurry attack alone?

thanks...

Flurry allows you to make 2 attacks, but you don't combine the damage for the purposes of Wolverine's power. So your last assumption of the 4 damage from a single flurry attack is correct.

The character needs to take 4 or more damage from an attack; flurry is 2 different attacks. For the SP to trigger, it has to be from 1 attack, not both attacks combined.