An ending where you succumb to become a mindflayer would not be a surprise...you would know you were going down that path. That wouldn't happen at random and of all the dozens/hundreds of permutations and possible endings, becoming a mind flayer, if it exists at all, is probably relegated to one, single ending/permutation where you need to choose every evil option, indulge the tadpole at every opportunity...etc. You would have to choose it, knowingly. As a cinematic ending, turning into an illithid would be dope AF.
