In StarCraft, the Protoss unit that attacks with energy blades is the Zealot.
Zealots are heavily armored Protoss warriors who fight in close combat using psionic energy blades mounted on their gauntlets. They are among the most recognizable Protoss units and form the basic melee infantry of the Protoss army. Their armor and shields allow them to withstand considerable punishment while closing with an enemy.
The Zealot is often mixed up with the Dragoon, which is a ranged cybernetic unit, or the Dark Templar, which uses permanent cloaking. High Templars are powerful spellcasters rather than front-line blade fighters. In StarCraft II, Zealots retain their signature blades and can later gain Charge, making them faster at reaching nearby targets.