5th-level Spell: Vorpal Weapon

Aspetheurgy (Transmutation)

You touch a weapon and grant it a merciless edge. For the duration the weapon becomes unbelievably sharp. Its attacks ignore resistance to slashing damage and it gains the Siege property, dealing double damage to inanimate objects and structures. If the weapon is mundane or is supernatural and has a bonus of +2 or less, its bonus becomes a +3 to attack and damage rolls.
Additionally, if the wielder scores a critical hit with this weapon which would leave a target with less than 50 hit points, it is decapitated and instantly killed.
Source: KCC

• Casting Time: 1 action
• Range: Touch
• Components: V, S, M (a melee weapon worth at least 1sp)
• Duration: Concentration, up to 1 hour
• Ritual: No