Maybe on a better day he'd get through this no problem, maybe even if he was genuinely angry at Bariyan rather than taking his frustration out on him and lacking any real killing intent aside Eridan's preference for stress relief through violence he'd be focused enough to resist.

But he hasn't slept much at all for the past eight months, and the rare times he does it does nothing for him aside cause horrible, horrible nightmares plagued by eldritch monstrosities and disturbing visions, ultimately leading to accomplish nothing but freak him the fuck out. He doesn't actually benefit from it at all.

So the exhaustion from months of sleepless nights gets to him once he feels himself become a little weary, maybe even aiding Bariyan's magic in putting him out. At first he just kind of staggers for a moment before ultimately succumbing to it and passing out, dropping to the floor in a heap.