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
can we change the background, now the heroine is in the domain of tentacles (I don't know), you can make a background of space, a background of a robotic laboratory (possibly with thematic manipulators that you can't just buy\choose), perhaps the mouth\stomach of a huge monster, maybe a milk factory, if you have an idea, throw it in too