gender change serum, race change serum, body type change serum (muscular, normal, loli, big mama), enlargement/reduction serum, breast milk serum, arousal serum, sleep serum, fetish change serum (I don't know, maybe lust will accumulate more with different effects)
yeah I was thinking of something like that maybe hypnosis serum or a bored serum that makes her seem annoyed or doesn't care, just stuff to change her mood.
not on the topic of serums, I just suddenly thought if a girl is a slime race and she has breast milk, then it will be possible to make it so that the milk is visible inside the breast
