A Kelpien raised alone by holograms on a dilithium planet, whose anguish at his mother's death triggered the galaxy-wide catastrophe known as the Burn.
Su'Kal is a Kelpien born to a scientist aboard a Kelpien research vessel that came to rest on a planet made largely of dilithium inside the radioactive Verubin Nebula. Exposure before birth left his body adapted to the nebula's radiation, and after the crew died a holographic program built to educate and protect him kept raising him in isolation for more than a century.
As a child, Su'Kal's grief at his mother's death set off a reaction in the dilithium that spread across the galaxy and destroyed most active warp cores: the Burn. In 3189 Discovery traced the source to the nebula, and Saru, Michael Burnham and Hugh Culber beamed into his simulation, where his distress threatened to cause another surge.
Saru stayed with him while radiation sickened the away team, helped him turn off the simulation and come to terms with his mother's loss, and then brought him to Kaminar to begin a new life among his own people.