Playing the LOTR campaign in Nightmare mode (more fool me). Had my first vaguely positive pass at Helm's Deep derailed by a Bloodied Beserker: " Forced: When BB is dealt a shadow card with no effect, either place 2 progress on the active location, or BB makes an additional attack against you".
Since there was no active location in play, Bloodied Beserker had 4 attacks on me before finally getting a shadow effect (boosting the last attack). I assume I was right in dealing a fresh shadow card each attack, as per FAQ 1.42?