During Elise's Emotional shock a few update ago, Minerva used this opportunity to possess her (She can possess people facing bad emotions)
Which led her to have her personnality altered which is why she started to be a bit more ruthless.
That said her cover was blown by Leonie's intervention, which led to Minerva having to give up Elise's body.
The scene was a bit eh, I do need to remake it !
Sometimes I write stuff a bit too fast.