Kells, or Kel in Eliksni culture, act as the political leader of their Fallen House, ruling their people and command their forces with an iron fist and usually commandeer their House's flagship Ketch. Kells are also known for controling their Houses' Ether supply through the use of an Elder Cipher.
They are mysterious figures rarely seen by lower ranks of the House and often viewed as mad, however the Kells travel a delicate path toward understanding and in the Old ways of the Eliksni, sought guidance from the Elders of House Judgement on codes of dignity and law. 
Only the strongest Fallen warrior leads the pack.  Kells maintain order among the House, whose subjects can often be aggressive. Their first command is a word and if unheeded, then the Kell's second command is the blade, resulting in docking.  Shamed Eliksni may later redeem themselves through brutal ceremonial combats such as the Archon's Forge or other means to prove their might.  Since the Eliksni culture has a love for Honor, the weak are Honor-bond into subservience and respect their Kell's authority like that of a sniper.
Kells also have access to better resources and eat better, sleep safer, and live longer. A strong Kell's power is described to be like the wind: swift, howling and everywhere at once, comparable to the Guardians. Kells are more stronger, faster, and intelligent, than the common Eliksni. If a Kell dies, the House collapses into a civil war between their nobility vying for dominance and kellship. Only the most powerful contender or when all opposition is gone can a new claimant assume control. When the Wolf Kell, Virixas, was killed by Mara Sov, three Barons fought against each other to become the new Kell of Wolves.
However it is possible that a House can still function without a Kell, as an Archon, Prime Servitor, or another Kell from a different House can assume command of the House.  Their loss severely weakens a House and demoralizes its forces, so for this reason, Kells are a prime target for enemy forces.
Prophecy of the Kell of Kells
According to a prophecy by the House of Rain, the Great Machine would crown a mighty warrior as the Kell of Kells, and rule over all houses. None but Skolas and Variks has ever attempted to claim this title for themselves.
Known claimants to Kellship
Houses without Kells
List of appearances