In StarCraft II, which Protoss unit can cast Psionic Storm?

In StarCraft II, the Protoss unit that can cast Psionic Storm is the High Templar.

High Templars are powerful psionic spellcasters rather than conventional frontline fighters. Their Psionic Storm ability creates an area of intense energy that damages units caught within it, making the unit especially effective against tightly packed biological forces.

The High Templar belongs to the Templar branch of Protoss society, alongside the Zealot and the Dark Templar. Unlike the Dark Templar, High Templars are not permanently cloaked. They also differ from Sentries, whose abilities focus on shields, force fields, and battlefield support.

Two High Templars can merge into an Archon, a powerful psionic combat unit. Players therefore often choose between keeping High Templars for spellcasting or combining them when immediate fighting power is more valuable.