I just beat it last night as a level 54 Madness Sorc with Xalek. My moronic companion kept dieing to the laser, and I couldn't handle the Archon's damage output (I'd run out of force just healing myself).
What finally worked for me was ignoring the ads completely, causing the Archon to spam his laser constantly; the attack is easily dodged, and as long as he's using it, he isn't damaging you directly, giving you time to heal and recover your resource.