Necromancer Wight

{2}{u/b}, {t}, Sacrifice a creature: The next instant or sorcery spell you cast has gravestorm. Activate only as a sorcery. (copy
it for each permanent put into a graveyard this
turn)
"I don't know what sort of eternal wellspring they draw from, but it's clear that the draugr carry
only the barest whisper of life in them"