Maybe the game is designed so you can get away with using the tadpole one or two times, more than that and....well just don't. I wonder if the hit will be per character or per party. If each character could get away with two shots of this tadpole that would make eight uses.
Swen could use it a few times before a message popped up saying that the tadpole reacted. I think those messages are the indication that the progression has advanced slightly. So you can use it, maybe twice without it advancing a stage, but the third use tips it over. We don't know how many stages there are.
