Shadow Blade of the War Mage (5e Equipment)
From D&D Wiki
Wand, rare (requires attunement)
From the depths of some dark abyss, this sword seems as if it is alive. Although the blade itself is not sentient, whatever created it seems to be a being of pure shadow. Whether it's creator's intentions in forging this blade were evil or not is unknown.
Although the sword appears to be a weapon it is forged of glass that radiates magic. If it is actually used to attack a creature in melee, it will shatter on contact.
While holding this glass sword, you gain a +2 bonus to the attack and damage rolls of your spells and to the saving throw DCs of your spells.
While attuning to this weapon, you must make a DC 16 Charisma saving throw or take 5d10 psychic damage, due to the blade's volatile nature.