Terraria (Wiki): Night’s Edge

The Night’s Edge is a melee weapon that pierces enemies and has the strongest damage among all swords.

The Night’s Edge is a post-Skeletron broadsword that stands out with the highest base damage of any sword before entering Hardmode. Although at 40 base damage, it equals the Volcano (desktop, mobile, console). The Night's Edge is capable of autoswing and can be upgraded into the True Night's Edge. A Night’s Edge can autoswing. Its attack reaches six tiles in radius. At an optimal distance, the Night’s Edge can pierce four enemies. However, multiple bodies will be damaged should they all line up for the player.

When normally used, the Night’s Edge emits purple particles that resemble flames, but the effect is more subdued and has a shorter duration. When the Night's Edge is swung, a purple aura follows the swing and extends the range at which it can hit enemies (desktop, mobile, console). The aura also rotates a second time on its own, extending its range even further and even covering the player's back. This aura can penetrate walls and break pots, but it cannot harm nearby enemies. A purple flash appears when the blade or its aura strikes an enemy. The Night's Edge aura functions as an extension of the blade, has no cooldown, and deals additional hits (desktop, mobile, console). The Night’s Edge’s attacks do not go through walls.

The Night's Edge has a few drawbacks compared to its parts despite being regarded as an upgrade:

• It is smaller compared to the Volcano and Blade of Grass;
• Its knockback is less than that of the Volcano, Light's Bane, and Blood Butcherer;
• In contrast to the Muramasa, it does not autoswing (old-gen consoles);
• It moves more slowly than Light's Bane and the Muramasa.
• It has no on-hit effects like the Volcano's On Fire! or the Blade of Grass' Poisoned.
• These drawbacks can be offset, though, by the damaging aura it creates when it swings, which lengthens its range and increases damage (desktop, mobile, console).

Combat-wise, the Night’s Edge can survive well into Hardmode with the Legendary modifier making it effective against multiple enemies and bosses. All Flask items will imbue their unique effects since the Night’s Edge is a melee weapon. 

The Night’s Edge is best modified with Legendary for overall stats improvement.