How about a whole team of Ritualists all casts 1 different kind of spirit (since if one spirit of pain is cast, a second one cast will cancel out the first one) then everyone selects their respective spirit, and when the Opponents get close, everyone simultaneously casts rupture soul on them?
I call it, the rupture bomb

in earlier trials, it proved not that great, it required LOTS of coordinated work and you have to pack the spirits all close together. Against the zaishen elite with just 4 people. With good effort we were able to kill at least one and good damage on the others... how would this fare in normal pvp with a full 8 ritualist group? it may not kill the ranged people, but i suspect the warriors and such would be toast, and afterwards you can just have your fun outnumbering way on the rest.
Destruction (rit skill) thrown in would be good too, or w/e one causes damage whenever you create a creature