Spellsword (Patreon)

Spellsword
Weapon (shortsword), rare

This item appears to be a shortsword hilt. While grasping the hilt, you can use a bonus action to expend a spell slot of 1st level or higher to activate the sword, causing a blade of pure energy to spring into existence. The sword remains activated for 8 hours, or until you deactivate it early using an action. Once you activate the sword in this way, you can use it as a spellcasting focus, and you are proficient with the spellsword for the duration.

You can use your spellcasting ability, instead of Strength or Dexterity, for your attack and damage rolls using this weapon, which deals force damage instead of piercing damage. If you activate the sword using a 3rd- or 4th-level spell slot, its damage die becomes a d8, and you gain a +1 bonus to attack and damage rolls made with it. If you use a 5th-level slot or higher, its damage die becomes a d10, and the bonus increases to +2 instead.

When you deactivate the weapon early using an action, the remaining magic stored within the blade erupts into a wave of energy. Each creature in a 10-foot cone must make a DC 15 Dexterity saving throw. A creature takes 3d6 force damage on a failed save, or half as much damage on a successful one. If the sword was activated using a 3rd- or 4th-level spell slot, the force damage becomes 4d8, or 5d10 if it was activated with a 5th-level slot or higher.

The blade emits bright light in a 20-foot radius and dim light for an additional 20 feet, and disappears if the sword is no longer activated or if you let go of the weapon. While holding the activated sword, you can use a bonus action to cause the blade to vanish or reappear.

My magic runs as deep in me as the cuts it leaves behind.