Heh, I just use Call Darkness against him.
Crow, Dark Whelpling and Brilliant Kaliri.
I start with the Crow, Call Darkness and see what he casts, if it's Whirlpool I swap to the Dark Whelpling to use Lift-Off avoiding a breath and the Whirlpool damage. If it isn't Whirlpool I use Nocturnal Strike and see what happens round two.
I might try this debuff method though as sometimes he just destroys me!
It's almost 6am and my brain is failing, the evil turtle who's name escapes me.
I've had him just cast Shield, Pump and then Wave until all my birds are dead. Then other times he just one shots them all in six rounds.