I don't think this answer is correct. I haven't done tera raids in a bit but I don't see why abilities like Lightning Rod or Storm Drain wouldn't work. Also, Huge Power definitely works, a commenter was just pointing out a bug that caused damage to the Raid boss to be displayed incorrectly (which doing quick research, it seems Play Rough is the cause).
I think you're getting confused by the OP in the Reddit thread mentioning abilities not working specifically when the Raid boss nullifies the effects of abilities for a turn.