Vondur's Guided Martyr

Vondur's Guided Martyr allows the user to utilize a corpse within a 60ft radius to create an explosion of necrotic energy. The corpse follows orders of the user and can move 30ft before exploding. The user must have knowledge of a corpse in range but does not require line of sight. There is a 15ft blast radius which deals 8d6 necrotic damage on a failed dex save, and half on a succeeded save. The spell does an additional 1d6 damage for every level the spell is cast above 3.