This article or section contains information derived from Co-op Missions, and should not be considered part of the official StarCraft storyline.
Supplicants are the most loyal followers of HighlordAlarak, and willingly sacrifice their life-force for him while in battle. They live to serve and die for those above them on the Chain of Ascension, at least until they gain enough power and influence to challenge them to Rak'Shir. They are fanatically loyal not to any single Tal'darim (though they will say they are), but to the Chain of Ascension itself.
Supplicants are available in Co-op Missions when playing as Alarak. They are produced in pairs, in a manner similar to zerglings (although more expensive). When Alarak is near death, he will automatically sacrifice a supplicant in close proximity to restore his health and shields. Ascendants can also sacrifice them to fully restore their energy.
While numerically superior compared to their zealot cousins, supplicants have much lower damage per second, possessing low range and terrible damage value that can be almost completely negated by enemy armor. However, a fully-upgraded supplicant can serve as an exceptional tank, particularly for a Tier 1 unit, with their shields in particular gaining up to 5 armor with 150 shield points and 75 health points, not to mention they're warped-in in pairs.
The player should always have a few supplicants, because Alarak can take large amounts of damage when focused on by bigger waves, and he will freely sacrifice more-expensive units if supplicants are not available. Additionally, their high supply count helps improve the potent Empower Me buff. However, care should be taken not to have one's army consist of too many supplicants; supply should be left open for Alarak's other units.
Combined with their short range ensuring they will be on the front lines, a properly-built army for Alarak will not be lacking for fodder to be sacrificed to the Highlord, while superior units lay waste from a distance. Consider supporting your army with War Prisms to create Pylon Power on the front-lines to warp-in reinforcements.