What is the real name of the Overwatch hero Sigma?

The real name of the Overwatch hero Sigma is Siebren de Kuiper. He is a Dutch astrophysicist whose experiments with a black hole changed both his abilities and his life.

Before becoming a hero, de Kuiper was a pioneer in astrophysics. A catastrophic experiment exposed him to unusual gravitational forces and left him psychologically damaged, while also giving him the power to manipulate gravity. He was confined in a secure facility and identified as “Subject Sigma” before being recruited by Talon.

Sigma’s abilities reflect his scientific background: he launches experimental hyperspheres, creates a gravitational barrier, absorbs projectiles with Kinetic Grasp, and uses Gravitic Flux to lift enemies. Players sometimes confuse his alias with his birth name; Sigma is the codename, while Siebren de Kuiper is the character’s real identity.