Vitale Medici is the son and heir apparent of Lorenzo Medici, and the backer of the Cirque de Cartes. Cerebella sees him as a father figure and is the uncle of one of the main characters. Namely, Filia.
Admittedly, takes over the Medici family after his father Lorenzo mysteriously vanishes from public life.
Manipulates Cerebella using her love and loyalty to him. His relationship with Cerebella isn't supposed to be romantic, but still, it's surprising to see how such an attractive girl's loyalty can be won by someone who is so plain-looking (being square-faced and slightly overweight) and a ruthless mobster to boot.
To the plot of her story. After seeing Cerebella's performance at the circus, Vitale gives him a mission to put his skills to the test: instead of seeking out the Skull Heart to obtain a wish, Cerebella's story instead follows her pursuit of Ms. Fortune and the retrieval of the Life Gem at the behest of Vitale.
Vitale also appears in Eliza's Story Mode, where she orders her, along with Cerebella, to retrieve Ms. Fortune's Gem of Life, due to that Eliza captures Ms. Fortune and kills Cerebella since Eliza does not She needs the Gem of Life because she can survive by absorbing the blood of others to be eternally beautiful and immortal.
Her story ends with her in bunny suit sitting on Vitale Medici's lap, who is congratulating her for exceeding his wildest expectations of her. Despite finally obtaining everything she was ever after, the final frame shows Cerebella looking remorseful for what she has done.