The third phase of normal difficulty Helya Trial of Valor Raid, Helheim’s Last Stand, loops without end. All tentacles are dead. Just repeated waves of mobs and fury-of-the-maw waves. Helya stays at 41% health and remains unattackable throughout. Is there a way to break the cycle to make Helya attackable? This is required for Trial of Valor: The Once and Future Lord of Shadows quest.
Well, go figure. Now it works. Logged out of Wow. Killed mobs slowly. Killed all trash. Damaged but did not kill the tentacles on the towers during the waves and presto!