From Destinypedia, the Destiny wiki
Command-Code Holders System Targetting
Cabal Slug Shotgun
Psionic Blast Nova Rupture Limited Flight High Durability Rapid Movement Psychic Melee Summon Cabal
Keymaster Psions are a Major Red Legion variant of the Psion. They can be seen deployed to a Proving Ground on Nessus and are charged with carrying and protecting Imperial Command Codes for the Halphas Electus Imperial Land Tank.