Im a Shadow Tank and I did it last night, 1 shot it. Rotate your CDs on each Frenzy and make sure you have a dedicated healer or two. First Frenzy I used Deflection, and the second one I used my Adrenal, Relic, Medkit, and Battle Readiness. It still hits for a ton, but its tankable.
Edit: I like the idea of it being toggleable. +1