Frostbrand

Frostbrand is a Hardmode Sword that drops from Ice Mimics found in Underground Snow biomes. Besides its use as a regular sword, it fires an icy projectile towards the mouse pointer when swung. This projectile emits a fair amount of light, is not affected by gravity, deals the same amount of damage as the sword itself, and can pierce through a single enemy. This ability costs no mana, but has a small cooldown. This sword could be considered to be an upgrade to the Ice Blade, due to its similar functionality and effects. The best possible modifier for this weapon is Legendary.

The Frostbrand is a rather powerful Hardmode sword, even when compared to the Excalibur: the former has slightly higher base damage, added ranged capabilities, is far easier to obtain (since no Hardmode bosses have to be defeated), only lacking in the continuous swing capabilities of the latter. It also can be more useful than the Beam Sword in some scenarios, because while the Beam Sword does slightly more damage, Frostbrand's projectile will pierce an enemy, hitting some bosses twice.

Trivia

 * The name "Frostbrand" is used in many Role-Playing Games such as Dungeons & Dragons.
 * It seems to be a more powerful version of the Ice Blade, and can be considered a direct upgrade.