Utani

Ngl I really want the damned whale from 5 to be forgettable but his annoying ass laugh is still stuck in my head 15 years later.

Also the fight with Eveline didn't feel like it was meant to be a boss fight. That felt more like you were meant to just survive until the injection did its job. She was already dying as you're fighting her but she seemed to be trying to create as she was being destroyed, trying to outrun her death. I wouldn't consider it forgettable, just wildly misunderstood