I’ll suggest you add mushrooms that makes the assistant grow as big as a city if + time, unlocks the destruction or government control ending base on how fast the assistant eats up the world and grows; if + mermaid turns assistant into a what ever you think it up yourself; if + monitor = giant muscle girl; if + milk= mega milker unlocks flooding or world of giants ending base on the milk industry (is set to random high or low every round); if + demon = Demon lord, unlock hellscape opening door to a new dimension with more ingredients if relationship is positive, unlock demonic world ending (she turns everyone into a demon, demon slayer reference) ending; if + cat = big cat no suggestions there; if + angels = goddess, unlocks Cornwall ending success or fail (Scp foundation reference, think of the event yourself) or unlock heaven gate (not a reference to su*cid thing) unlocking more ingredients or interactions with other characters.
I know it’s stupid sorry, but maybe you should add an ending for every pure transformation