Sven is the stoic Norwegian Voltron Lion Force member who is the initial pilot of the Blue Lion. Sven's full name as revealed in Devil's Due Publishing comics is Sven Holgersson.
Voltron: Defender of the Universe continuity
Sven was part of the scout team, under Keith's command, sent by the Galaxy Alliance to planet Arus. He and the others had witnessed a massive bombardment by Planet Doom, and he was captured along with the others.
After escaping from Planet Doom, he and the others made contact with Princess Allura and Coran in the Castle of Lions. He was assigned to be the pilot of Blue Lion.
Sometime later, he had rescued Lance from an attack by Haggar, and ended up seriously injured. Eventually, he was transferred to a hospital on another planet. But Doom attacked that planet, and Sven was captured and taken as a slave to Planet Doom.
He later reunited with the Voltron Force when he helped Romelle escape from Planet Doom. Sometime after his escape, he joined Romelle instead of flying Blue Lion (control of which passed to Princess Allura) or otherwise serving the Voltron Force in a reserve capacity.
He was later part of an advance force, led by Romelle, to conduct operations on Planet Doom prior to the invasion. He was once again seriously injured after a confrontation with Prince Lotor.
Afterward, on a few occasions he would help the Voltron Force in foiling Zarkon's attempt to fill in the power vacuum left behind with the destruction of Planet Doom and its Drule Empire, and even flew Blue Lion again during an attack on Galaxy Garrison by Lotor.