Talk: Arch-Amahn Wretchedcorpse

Prep: Clear out most or all of the adds in the bay to make the named fight easier.
Mob: Arch-Amahn will spawn dummy-adds that slowly walk towards him during the fight and will ignore you unless engaged. If they reach him, they spawn adds that will attack you. If you have high dps, just ignore the adds. If you wish to play it safer, mezzing or rooting the adds is both feasible and effective. Tank & spank.