So it turns out Bulette is straight-up broken.
What you were expecting to happen, and what actually happened?
After Bulette pushes someone to the back, he’s supposed to damage the new first enemy. Problem is, he aims all damage at the slot where the first enemy used to be. So if that slot is now empty, no damage is done at all.
What are the steps to make it happen again?
Use Bulette against the first surviving enemy when the spot below them is empty.
PS: Fizzbang is still broken too, albeit on purpose. Make her explode fewer gems and boost less so the stupid either/or can be nixed.