Capture Soul

You surround a creature in range with a foreboding force that threatens to seal its soul. If the creature is killed within the duration, it must make a Wisdom saving throw. Any creature that can take legendary actions or has the Legendary Resistance feature automatically succeeds on this save. A creature automatically succeeds on this saving throw if it is unintelligent or doesn't have a soul; this includes constructs, most beats, certain types of undead, and other creatures subject to DM discretion. Any type of poe, ghini, ghost, or other spectral form of undead that doesn't meet a previous condition automatically fails this save.

On a failed save, you rip from the creature's corpse a permanently-created poe soul which is sealed in the container used as the material component of this spell. Although this item is inanimate, it represents the creature's literal soul, which by your action cannot return to its body. If this soul is consumed or remains contained, the creature cannot be brought back to life (nor reanimated as a spectral form of undead) except by a spell of 6th level or higher. If such a spell succeeds, it destroys the created poe soul if it still exists.