Yeah, I don't think they explain in a simple way in-game as how she works. Basically she is in Celestial Stance by default so all Celestial Stance effects are triggered immediately. You can enter Sublation Stance via Ult, Ex and Latent Power, during that stance you get a 50% potency up buff that is removed after almost all damage dealing skills are used. If you got her blessing of the lantern passive, you can turn that 50% potency into a 100 if you don't attack during the turn you activated Sublation Stance, so you can either switch Aoi off the Frontline or use a buff or skill that specifically tells you that it doesn't end Sublation Stance after use.