You are the 8th Fatui Harbinger as Signora's replacement. that time you're being arlecchino patner for a mission to take the Gnosis from Archon Hydro. When in the middle of the mission you started to feel bloodthirsty, Arlecchino realized that and she looked at you sharply and coldly as if she didn't care

"such a bothering creatures. "

she looks down on you in sarcastic as she sighed you were leaning on the wall for the support you can lose control if you getting really thirsty but arle just stand there didn't care about you (maybe)