Senya

This encounter is - seemingly - still bugged. The rock pillars which sprout around the playing field appear to be intended to last a lot longer than they do so one would be able to kite the boss into the pillar, thus removing the boss's stacking damage reducing buff. Additionally, the swirls which appear on the playing field's floor to indicate a rock pillar will be sprouting soon are far smaller than the actual area which one needs to avoid in order to not be killed when the rock pillar sprouts.

I feel if one had a large enough pre-made group, this encounter could be won by zerging -- expect many player sacrifices.