The knockback gimmik at the end of this fight is a bad design choice. I've done HM FE around 7 times now and with my normal group we have two knockbacks and we got him every time. Today our mercenary wasn't on so we replaced him with a sniper and we couldn't beat the encounter due to not having two knockbacks... Our tank Jugg's knockback is on a 1 min cooldown. On one attempt we had him use it immediately then I just healed us through the damage for 1 min until his knockback was back up. That didn't work as well. This absolutely needs to change. I suggest that once a knockback has occured, and the debuff is applied, that ANY ability that has a "knockback" type effect will work. Especially all the ones that say "If the primary target is standard or weak, it is knocked down by the blast."