from Svens most recent interview it sounds like its a "Dark side" option rather than a failure state.
we also know theres a cult using the tadpoles to mindcontroll people so maybe its something in the vein of becoming an evil puppet master so to speak.
I still find it odd that mindfalyers rather than demons or literaly any other evil thing in dnd is the "evil temptation" angle, but ill see where it goes.
if you can actually become a mindflayer (which makes very little sense) then id be positiveley surprised
