Night's Edge

The Night's Edge is a high-end melee weapon, crafted at a Demon Altar. It requires four of the currently most powerful sword-class weapons to craft: a Light's Bane, a Muramasa, a Blade of Grass, and a Fiery Greatsword. It has the same lighting effect as the Fiery Greatsword as when swung it creates light, but it seems the effect is more subtle and does not last as long.

It has a very slow attack speed, deals 40 damage, and has about the same reach as a Muramasa. It can be a devastating weapon, as it deals about 72 damage per second. However, due to its low attack speed, enemies don't fall quite as quickly as they would if using the Muramasa. Using Feral Claws and/or Shadow Armor with Night's Edge can prove to be a very dangerous combination.

Putting any of the above four weapons in the Guide's "Crafting" option will reveal the full recipe and Demon Altar requirement.