The user can permanently destroy/annihilate souls and/or spiritual beings that do not have a body, without affecting the body, which causes the targets to die without possibility of Resurrection, but some may transform into a soulless being instead.
Invincible Stars/Starmen/Super Star (Mario series)
Ancient Athame (Charmed comic)
Godkiller (Drive Angry)
Silver Arm (Fate/Grand Order)
Azrael's Blade/Flaming Sword (Lucifer)
Soul Gem (Marvel Comics)
Olympian Crystal (Once Upon a Time)
Universal Killswitch (Transformers)
Soul Shredder (Your Pretty Face Is Going To Hell)
Enders (Angel & Faith) utterly destroy the souls they consume.
Ichibē Hyōsube (Bleach) using Futen Taisatsuryō to completely destroy his foes with blackness, that not even their souls can reincarnate.
Quincy (Bleach) are feared for being able to destroy the soul of anything they kill, preventing the victim from returning to the cycle of reincarnation.
The Ancient Athame (Charmed) is imbued with a spell powerful enough to destroy souls.
Superman (DC Comics) using Counter Vibration to destroy Darkseid's spirit, permanently killing him.
Beerus (Dragon Ball) using Hakai to erase the ghost of Dr. Mashirito.
The Godkiller (Drive Angry), Satan's personal gun, can completely destroy the souls of others.
Mard Geer Tartaros (Fairy Tail) casts the Memento Mori, curse that completely destroys both the body and soul of its victims as Mard Geer described neither alive nor dead, simply erased.
Azrael's Blade (Lucifer) is a weapon so powerful it can kill and eradicate the souls of angels and possibly the Goddess of creation.
In addition to giving the subject a death field alongside making them temporarily invulnerable to most forms of damage, the Invincible Stars/Starmen/Super Star (Mario series) can also obliterate Boos so they won’t return to fight again.
The Olympian Crystal (Once Upon a Time) is so powerful that it can destroy anything, even gods and human souls.
Soul Eater (Valkyrie Crusade) can consume and annihilate souls.