Funny thing is, when they turned Morgan's berserk to be party-wide, they nerfed its bonus from doubling damage to +20%. You need one of her relic weapons to change the bonus back to +100%. (said relic weapon's old effect was to change the berserk from single target to party-wise :P)
Without said weapon? Well, the original guaranteed-triple-attacks + berserk combo probably isn't too happy about that change.