Alsia's capture soul (v1.1)

by casting this spell, you summon the ghost of a long dead person. you must know the person's name and how they died to cast this spell, and this spell must be preformed at night. At the end of the ritual, the spirit must pass a wisdom saving throw against your spell save DC +1 for every 100 years the soul has been deceased(to a maximum of 800 years). If the soul fails the save, the soul becomes bound to your chosen vessel. if the soul passes, it becomes automatically hostile and attacks the person who summoned it.