That sounds hilarious.
You should talk about this hilarity.
I
must hear it.
The Gracious Aunt is a nemissary slash mortwight who was one of the first antagonists encountered in my Gloam game. She is an assassin who fights mainly by possessing corpses (she does not in fact have the Materialize Charm). She's managed to survive several encounters with the Solars because she's dangerous enough that players usually destroy her quickly, but not dangerous enough that they go through the lengths required to set up the killing blow by someone with Ghost-Eating Technique. They just wreck her current vessel and she goes away. And then she comes back.
The players killed the Dragon-Blooded to which she was loyal, and ever since she's wanted nothing but revenge. She realizes she isn't strong enough to take on the whole group, so she used tactics like "poison their meal and possess your handmaid" to compensate for her lack of power. Oh, and she devoured souls and bathed in the power of Gloam's corruption for more power until she mastered Ebon Shadow Style. And then she almost killed the Twilight's Dragon-Blooded waifu.
Ein's player commented that she was basically a player character. Driven by revenge and killing shit to gain more and more power beyond her station.
Anyway, she got in touch with the main antagonists of the game and used the power of Gloam's city father to lure Ein (whom she considered the weakest fighter of the group, and whom she knew couldn't destroy her spirit form) into the building where they had first fight. Both Ein and the Aunt abused stealth, but the Aunt had a plan to draw him out of the shadows: child hostages she was willing to push to their deaths from the catwalks above the room.
She didn't expect the savior of Gloam to choose to let the child fall and instead take advantage of that moment to stab her in the back. Especially because he was only stabbing her vessel, and she immediately went and possessed a new one while Ein tried to see if the child was still alive.
They had a pretty interesting stealth battle but Ein was laboring under the creeping realization that
he could not kill her. He could only destroy her current corpse and she would just go and find a new one until she ran out of Essence, at which point she would just fuck off. There was no win condition for him and there definitely was a lose condition, as her stealth attacks put enough pressure on him to run down his Essence.
At least until the player realized that he had just recently purchased the pinnacle Evocation of Heartbreak, his starmetal dagger that cut through emotions and passions. And that he was fighting a ghost.
At that point he flared his anima (a pretty huge deal for his discretion-obsessed character) to force her into the light and set up an attack which destroys the Defining Intimacy of Revenge that was the entire reason she was fighting in the first place.
In doing so Ein blew out all his Essence and Initiative and broke any chance at stealth, leaving him wide open for a fatal counterstrike. He banked everything on this, and hit home, destroying her thirst for revenge.
And with him at her mercy the Gracious Aunt just... Stared. And dropped her dagger.
And passed into Lethe.