Divine seal+Regen+Asylum+One heal if the tanks need.
Switch Cleric stance
Switfcast Holy=> Aero=>Assize=> Spam holy=> Stone III when 2 add left.

Tanks is low hp=> benediction if you want dps more
=>Switch cleric stance off and Tetra/Cure/regen

Repeat. But the most important thing IS TO ADAPT. Paper tank, don't try to dps unless you are sure you can.