Terraria (Wiki): Blue Phaseblade

The Blue Phaseblade is a melee weapon that pierces enemies.

The Blue Phaseblade's color is determined by the kind of gem used to craft it, and there are 7 (desktop, console, mobile) / 6 (3DS, old-gen consoles) different color variations with identical statistics. Since no other sword is specifically identified as a "Meteorite sword" and Meteorite Bars are required to craft it, the Phaseblade can be considered the Meteorite-tier ore sword. 

The Blue Phaseblade is the weaker version and one of the key components in crafting the Blue Phasesaber. A Blue Phaseblade cannot autoswing. Its attack reaches four tiles in radius. At an optimal distance, the  Blue Phaseblade can pierce two enemies. However, multiple bodies will be damaged should they all line up for the player.

When normally used, the Blue Phaseblade emits light, making it suitable for exploring caves, finding ores, and lighting dark places when traveling. The Blue Phaseblade’s attacks do not go through walls.

Combat-wise, the Blue Phaseblade's damage output and speed make it effective against waves of enemies. All Flask items will imbue their unique effects since the Blue Phaseblade is a melee weapon.

The Blue Phaseblade is best modified with Legendary for overall stats improvement.