This can be a little tricky. With all the four base personas (Lilim, Vetala, Incubus, Succubus), none of them can learn Mabufudyne innately. This means you need to create one of them via fusion and inherit Mabufudyne from another persona. With the four base personas, only Succubus can learn Mabufudyne.

Consider the following combinations for Succubus. One of the base personas for Succubus SHOULD HAVE Mabufudyne.

Empress + Chariot\ Death
Emperor + Justice
Hanged Man + Death
Lovers + Death
Magician + Chariot\ Hanged Man
Strength + Tower
Temperance + Devil