The Diabolos Hollow fight in Dun Scaith uses several mechanics to put a definite focus on survival over dps. DpS is good but surviving the fight is more important.

At the start of the fight the Auto-Crit Shield will let Diabolos flatten tanks quickly if they are not in tank stance and don't use cooldowns. If the tanks fall others are usually quick to fall soon after and wiping was very possible.

During the final phase when Diabolos gets the Double-Edge buff that allows for more damage dealt but at the cost of taking massive amounts from the attached DoT so the fight becomes more about the alliance surviving long enough for Diabolos to kill himself once the phase begins.