Since it has been stated that multiclassing will be available in the release version of the game and given how the tadpole power you get at the moment depends on your class, how would (should) this particular mechanic work if you have more than one class, especially considering how there's a promise of more powers granted down the road?
My guess is that it ought to give you the power for the highest level class the character posesses at the moment of obtaining it, as otherwise it'd give the character far too many "once per short rest" actions to spam in a pinch, and going for something like giving everyone applicable one druid level so they can all turn into intellect devourers and focus enemies with the, well, devouring attack is only a single example of a cheese tactic it might lead to creating should it not be at least somewhat restrictive.
