Glitch in Alliance Campaign?

IchigosGigai2k14

Every time I go to do Alliance Campaign, even if I'm with a group of three, theres a thing at the end where if one of us doesn't defeat an opponent fast enough, the opponent comes back and the fight starts going really slow and drawn out, like, 20 damage is dealt at a time, until the less powerful fighter wins....is that a glitch or is that supposed to happen? Sommebody explain, please...