If 4 Threat Peter Parker Spider Man makes a defense roll that comes up Skull, Skull, Blank (and has no access to Skull modifications) can he reroll the single blank, or can he not reroll at all? His ability does not say "up to two dice" and if he can't modify skulls then he can't reroll more than the one blank, but his ability says exactly two defense dice may be rerolled. This also applies for if the roll comes up as Skull, Block, Blank- does he have to also reroll the block if he wants to try and reroll the blank in order to meet the 2 die criteria?
