Fire/Poison
Ice/Steel is hardly a "stereotypically bad" typing. Ice/Rock, on the other hand, lacks any saving grace outside of great offensive presence, and will have a tough time distinguishing itself from the already solid Mamoswine. Fire/Poison at least offers some unique rolls, such as immunities to Will-O-Wisp and Toxic. There are unique roles we can give this sort of Pokemon that make it good by playing to the strengths of its poor typing, rather than in spite of it.