Who Counters Seaside Bellona in Epic Seven?

Empyrean Ilynav, Lionheart Cermia, Aram and other hard counters counter Seaside Bellona. Her control comes entirely from debuffs (Unhealable, Unbuffable, Defense down, Provoke); an ally cleanse wipes them off and undoes the lock she just spent her cooldown on.

Cleansers: Her control comes entirely from debuffs (Unhealable, Unbuffable, Defense down, Provoke); an ally cleanse wipes them off and undoes the lock she just spent her cooldown on. Immunity holders: A pre-emptive Immunity buff blocks her Unhealable and Unbuffable outright, and since her dispel hits before the debuffs, immunity reapplied after the strip neutralizes her threat. Burst before her cooldown comes back: The buff-strip plus Unhealable combo lives on her third skill with a five-turn cooldown; rush her down or race her in the window when it is unavailable and she has only a single-target basic and her Focus-gated attack. Wide area pressure on her team: Her damage reduction passive shrinks as allies die, so heavy area damage that thins her backline both weakens the team-wide mitigation and slows the Focus generation her area attack depends on.

Healers and lifesteal sustain teams: Her area attack inflicts Unhealable for two turns, so healing skills and life-drain stop restoring Health, and because it ignores Effect Resistance it lands even on resistant targets. Buff-stacking and barrier comps: Her area water attack strips all enemy buffs before applying its debuffs, wiping shields, Immortality and other stacked protections, then inflicts Unbuffable so they cannot simply re-apply them. Revive and immortality strategies: Combining the dispel with two turns of Unhealable shuts off the recovery these teams need to come back, and the buff strip removes any active invincibility or barrier keeping them alive. Squishy front-liners: At five Focus her passive unleashes an area fan attack with a 75% chance to decrease Defense for two turns, softening the whole enemy team for her allies to finish.