Goldnight (5e Equipment)
From D&D Wiki
Weapon, Legendary (requires attunement of a good aligned character)
Goldnight is a longsword said to be forged and used by a Solar angel who lost the blade long ago. The words "Even the wicked have nightmares" is inscribed on the handle of the golden sword. This weapon deals 2d8 radiant damage to all enemies but celestials, which it has no effect on and seems to pass right through them.