Demon Blade

As a herald of archdemon you get to summon his sword into your plane. You can do so as reaction to being hit by burrowing deeper into this pain, losing additional 1d4 + spell level of HP. This magic sword lasts until the spell ends. It counts as a simple melee weapon with which you are proficient. It deals 2d8 psychic damage on a hit and has the finesse, light, and thrown properties (range 20/60). In addition, you deal additional damage equal to HP lost as necrotic damage, as the sword is strenghthened by your sacrifice. When you use the sword to attack a target that is in dim light or darkness, you make the attack roll with advantage.

If you want to summon the sword into your plane without being hit, you can do so by paying with your blood equal to (Max HP dice + spell level) using your bonus action.

If you drop the weapon or throw it, it dissipates at the end of the turn. Thereafter, while the spell persists, you can use a bonus action to cause the sword to reappear in your hand.

At Higher Levels. When you cast this spell using a 3rd- or 4th-level spell slot, the damage increases to 3d8 and HP dice increases to 1d6. When you cast it using a 5th- or 6th-level spell slot, the damage increases to 4d8 and the HP dice increases to 2d4. When you cast it using a spell slot of 7th level or higher, the damage increases to 5d8 and the HP dice increases to 1d10.