Khalis

Khalis is a powerful Khaydarin Crystal. It is light blue in color and possesses the energy of the Dark Templar. It is a twin of sorts to the Uraj crystal.

Creation and Differentiation
The Khalis crystal was one of two shards of a monolithic Khaydarin Crystal, created by the Xel'Naga and entrusted to the Sargas Tribe. Over time, it diverged from its Uraj counterpart. The Khalis remained with the Sargas tribe until the Rogue Tribes, ancesters of the Dark Templar, were banished from Aiur. Shortly afterward it was discovered that the exiles had stolen the Khalis and taken it with them.

The Khalis on Char
Some time after the Dark Templar settled on Shakuras, they (like the Protoss of Aiur) encountered the probes of the Zerg. Further investigation eventually led the Dark Templar to Char. The Dark Templar, like their kin back on Aiur, were greatly concerned about the Zerg and chose to test themselves in battle against small bands of Zerg on Char. The Zerg proved frighteningly resilient and numerous, and so the Dark Templar brought the Khalis to Char so that they might try to wield its energies against the Zerg. Although the Zerg did take casualties, the Overmind soon launched a massive counterattack, overwhelmed the Protoss, and claimed the Khalis. The crystal was left behind on Char when the Swarm went to invade Aiur.

During his journeys on Char, Zeratul detected the powerful crystal, but he was unable to retrieve it.

Psionic Weapon
During StarCraft Episode IV, Shakuras was overrun with Zerg. In order to cleanse this infestation, the Xel'Naga Temple on the planet needed to be activated, but it required two crystals, the Uraj and the Khalis, to do so. Raszagal ordered her Protoss warriors to let nothing stand in their way in order to acquire the crystals.

Zeratul, Artanis and their new ally Infested Kerrigan, along with the Protoss fleet, arrived on Char in order to retrieve the crystal. Unfortunately, its powerful psionic emanations attracted the Zerg. The new Zerg Overmind was situated very close to it, along with a huge swarm of minions.

Infested Kerrigan suggested snatching the crystal, but Artanis believed his forces could weaken the second Overmind enough to pacify the Zerg for a short period of time so they could retrieve the crystal. Zeratul praised Artanis' bold idea. Kerrigan said either plan would work, and provided assistance by taking command of a Zerg Hive Cluster, which worked alongside the Protoss. After a fierce battle, the crystal was retrieved and taken to Shakuras.

Upon returning to Shakuras, the Protoss forces broke through the Zerg's hive clusters to reach the Xel'Naga Temple. Zeratul carried the Khalis himself, and successfully used it to activate the temple and scour the Zerg from Shakuras.