death to all

a streak of of black streams too a 10 foot spot around a place in range. the creatures in the area must take a wisdom saving throw, taking 6d8 necrotic damage. also  on a failed save, the creature will turn into a necrotic creature. see stats below. the soul goes to the bone, and you control the monster(s). the souls can be released with a cleric ritual. the ritual takes 200gp in ruby dust