Cascading Death

This spell does 5 D10 Necrotic damage to a creature the caster targets within range. If the target makes a constitution save the damage is halved. If the creature is reduced to 0hp, the spell uses its life force to jump to its next target.  The hitpoints that the target creature had before the spell, are inflicted as Necrotic damage on the hostile creature with the lowest hit points within 20' of the first target. If the second target is reduced to 0 hp, its life force is used to attack a third hostile target with the lowest hp total within 20'. This continues indefinitely until a target creature survives the damage, there is no target within range for the spell to jump to, or every possible target is dead. The spell then ends.

Cast at a higher level, the initial damage of the spell is increased by 1D10 for every level above the 5th.