I'm thinking maybe a spinner if you don't need him, but your team doesn't seem to have a major weakness towards any of the hazards, so maybe a wish passer like Vaporeon. Can wish stuff off, absorb water moves directed towards Gliscor (roserade and Empoleon I know, but it never hurts), and it can run protect/toxic along side Gliscor.
Has he been useful? Steel never hurts and two bulky steels seem scary.