Ina, the cheating heroine.

You yourself said it's imba, but not a cheat. Heroes is a game where, with skill, you can win in any situation. The interesting part is finding that unique strategy and being able to apply it. Because there aren't any overwhelmingly powerful heroes, creatures, artifacts, or cities. Yes, each has its advantages and disadvantages, but everything is generally balanced; you just need to be able to find that balance.