Influenced by the sea beast's consciousness, Billow marks enemies with less than 30% HP as "prey." Billow's skills and normal attacks deal an additional 15% true damage to the "prey."

Billow briefly harnesses the power of the sea beast to enter the "sea beast form", gaining 60 movement speed for 3s. When the duration ends, he bursts out of the water, refunding 50% of the cooldown. While in the "sea beast form", casting Submerge causes Billow to surface and execute a quick strike, dealing 300 (+120% of bonus AD) physical damage and applying a 50% slow for 1.5s to the target.

In Creeks, the sea beast form has no time limit. If a "hero prey" appears within 15m of him, the movement speed boost is further increased by 450.

Billow attacks nearby enemies, slashing their wounds twice, dealing 150 (+35% additional AD bonus) physical damage. Upon casting, Billow gains 1 mark, and gains an additional mark for each enemy hit. Marks cannot be stacked repeatedly on the same enemy, up to a maximum of 3 marks. Hitting an enemy restores 90 (+35% AD bonus) HP (effect is halved on non-hero units). Normal attack will make Billow pursuit the enemy and consume 1 marks, dealing 50 (+75% AD bonus) physical damage and restoring 90 (+35% AD bonus) HP. Each pursuit reduces the cooldown of Slit by 10%-20%.

Billow hurls a dagger imbued with the power of the sea beast, applying a 90% slow to enemies in its path for 0.5s. He then unleashes the sea beast's power, dashing to the dagger's location and dragging enemies along the path to the endpoint for execution, dealing 550 (+170% of bonus AD) physical damage.

When cast in the sea beast form, Oceanic Fury skips the dagger throw and directly triggers the follow-up effects, reducing Submerge's cooldown by 50%.