Nyan's Gambit (5e Equipment)
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Wondrous item, very rare (requires attunement)
When you cast magic missile while wearing this leather glove, the spell produces one more magical dart per level of the spellslot spent to cast it, and the damage type of the spell changes to lightning damage.
A knockoff, Uncommon rarity version of this item also exists, which only adds one missile to the spell, regardless of the level it's cast at.