Two entries with the name Helis.
Helis
Helyes, Helys
A knight who fought in Arthur’s forces against the Saxons. He was the steward of the Castle Roestoc and the brother of Mabonagrain.
Source
Le Livre d’Artus | Early 13th century
Helis
Elyse
A cousin of Arthur.
When his father, Ardan, was defeated by Palamedes in joust, Helis swore revenge. Helis, however, was also defeated.
Sources
Palamedes | c. 1240
Prose Tristan | 1230-1240
Le Morte Darthur | Sir Thomas Malory, 1469-1470