I believe I read in an interview that these "tadpoles" are unique. I agree that it is likely that the "issue" with them will mostly be wrapped up in act 1. This can happen in 1 of 5 ways as far as I can imagine. The 1st, you transform into a mind flayer and play the game on the side of mind flayers (unique dark spin that I approve of) or alternatively game over. The second would be you bend the tadpole to your will (at least temporarily) to retain the powers they grant you. The third would be you become cured of the tadpole from an outside source, the 4th you reject the powers of the tadpole limiting its influence in you. The 5th would be the tadpole takes over your body, turns you into a mind flayer, sending your soul to the afterlife where you fight to return to the world of the living and reclaim your body.
