Frontliners Tip
Use your "CC reduction" card + "Resilience" to deny point pressure from "Grumpy Bomb".
BK feels relatively safe you while stunned. "Jumping out" of stun earlier, works like surprise effect & confuses him.
Do To Ruam's 75% resistance while charging, stacked on top of his potential 4000 soul armor from soul harvest, and 750 additional max health (from sinister allies) implies ruam can stay at a consistent 9250 to 16,187.5 hp... Sooo, Stun him ALOT....