Sven (Space Vikings!)

Sven was a human inhabitant of the colony planet Lindis, alongside his brother Bjorn. On the instruction of Odin, we was captured by Thorir and converted into a Viking.

He was later sighted by the Tenth Doctor and Bjorn. When Bjorn tried to free his brother from the Viking control by ripping off the helmet that was sending him instructions the helmet malfunctioned, electrocuting and killing him. (COMIC: Space Vikings!)