The most powerful solo carry in Honkai: Star Rail. Phainon transforms into the god-like Khaslana via his Ultimate, expelling all allies from the field and decimating enemies with 8 enhanced extra turns, Physical Weakness implant on all targets, and astronomical damage multipliers that scale directly with every buff he receives from his team.
Deals Physical DMG equal to 50% of Phainon's ATK to one designated enemy. Rarely used outside of specific SP management scenarios since his Skill is almost always the better choice for building Coreflame.
Gains 2 Coreflame points and deals Physical DMG equal to 150% of Phainon's ATK to one target and 60% ATK to adjacent enemies. Every Skill use directly charges the Khaslana transformation. This is Phainon's primary Coreflame generator between Ultimates and should be used whenever SP allows.
Costs 12 Coreflame (not Energy). Transforms into Khaslana, deploys Territory "Ruinous Irontomb," and removes all allies from the field. Every enemy immediately gains Physical Weakness. Khaslana receives 8 extra turns at 60% of his base SPD. On the final extra turn, launches a massive Final Hit dealing 480% ATK Physical DMG distributed across all enemies as Ultimate DMG.
Phainon's passive engine. When any target uses an ability on Phainon, he gains 1 Coreflame point. If that target is a teammate, Phainon also gains +15% CRIT DMG for 3 turns. When Khaslana transforms, he gains 4 Scourge points and his ATK increases by 40% and Max HP by 135%. After each attack, restores HP equal to 20% of Max HP. On a killing blow, Khaslana cannot be knocked down and restores 25% HP instead, then immediately launches the Final Hit.
While Phainon is in the team, increases Max Technique Points by 3. When used, consumes 2 Technique Points, attacks all enemies nearby, and after entering combat: regenerates 25 Energy for all allies, grants 2 Scourge and 1 Skill Point. Deals 200% ATK Physical DMG to all enemies at wave start. Instantly defeats normal enemies without entering combat. No cost if no enemies are hit.
Phainon is designed to be played sustainless. During his transformation he has 75% DMG reduction, CC immunity, and self-healing after every attack. His A4 trace rewards teammates who use healing or shields, so support characters that buff AND heal offer double value. Sunday is his single best partner.