When battle starts, immediately gains 5 point(s) of Slashed Dream and applies 5 stack(s) of Crimson Knot to a random enemy. When Slashed Dream reaches its upper limit, for every point of Slashed Dream that exceeds the limit, gains 1 stack of Quadrivalent Ascendance. Enables Quadrivalent Ascendance to stack up to 3 time(s).

When there are 1 or 2 Nihility characters other than Acheron in the team, the DMG dealt by Acheron's Basic ATK, Skill, and Ultimate increases to 115% or 160% of the original DMG respectively.

When the Ultimate's Rainblade hits enemy targets that have Crimson Knot, the DMG dealt by Acheron increases by 30%, stacking up to 3 time(s) and lasting for 3 turn(s). And when Stygian Resurge triggers, additionally deals DMG for 6 times. Each time deals Lightning DMG equal to 25% of Acheron's ATK to a single random enemy and is considered as Ultimate DMG.