Nova has been shot in the face, you literally can't hit her with melee attacks (attack bar doesn't appear) and with guns you need to aim a three pixel wide attack bar with ice sliding mechanics like in Mario. So I saved all my mana and threw spells at her. (two hits per turn or savescum back)
https://files.catbox.moe/kgc931.mp4 I dedicate this victory to Lin. It was actually not that hard since you can save every turn.
