I forgot the actual details, and had a bunch of typos in that post. She killed a bunch of underlings while trying to get to the CEO, but didn't actually kill him. She pheromoned him into giving a confession for his various crimes.
It was Batman: Poison Ivy #1 by John Francis Moore. She was still a villain because her main motivation was "they ruined my paradise island," but Batman ended up assisting her for a bit (and arresting her at the end) because the weapons corporation was brazenly breaking the law in hunting her. The story even had a little of the post-crisis "obsessed with having a crush on Batman" characterisation in it.