I just watched this video about the Seneca effect, which is basically how it's hard to become a master but one single mistake can make you lose everything. Or how when we get complacent we can lose our high positions.

And since I have a Seneca, I want to put her through it. ?

She's really good at potions and alchemy and I was thinking that after some successes she has a huge disaster.

Another idea which could work with the cult group is that they take up a project and Seneca makes a mistake and the others kinds view her as a loser now and she's sidelined.