In the Tehlin religion, Tehlu is a paternal god, recognized as the creator and ultimate judge.
In The Chronicle
Tehlu has many different facets in the world, but is best recognized as the god of the Tehlin Religion. Throughout the text this is the most acknowledged religion, with churches and followers spanning the empire of the Four Corners of Civilization. Characters such as Chronicler and Trapis appear to be affiliated with the organization, the symbol of which is an iron wheel. Little is known of the officially recognized doctrine, however the church does take part in some rule of law, as witnessed when Skarpi is arrested for heresy and when Kvothe is charged and tried for misdeeds at The University.
According to Trapis, a follower of the Mender Heresies, an off branch of the officially recognized Tehlin doctrine, Tehlu became angry at mankind for their wicked ways. He then chose the only pure person in the world, a virgin named Perial, to bear a mortal form of himself, called Menda, into the world. After his birth, he grew into adulthood within a span of days. He then went through the world decimating evil, offering people a chance to repent their wicked ways, and destroying demons. Eventually, he had eliminated all the demonsin the world except the most powerful, Encanis. Tehlu pursued Encanis through six cities, before finally trapping him in an iron circle and burning him in a pit of fire, though he was forced to sacrifice his mortal form to do so.
In other folklore, Tehlu is not regarded as a god, but instead a ruach in the company of other legends such as Selitos and Lanre. After the madness and betrayal of Myr Tariniel by Lanre and The Chandrian, Tehlu is said to accept a mantle from Aleph along with several other heroes of the Creation War. This transforms him into a winged entity of great power, referred to within the text simply as an Angel, invisible from normal eyes. He and his brethren are charged with watching over the world and meting out justice in this new form, and he is said to be the greatest of them all.
It is speculated that there is some connection between Trapis's story of Menda and Skarpi's story of the betrayal at Myr Tariniel. Similarities exist within both stories, such as the destruction of six cities and the description of Encanis to that of Haliax after being cursed by Selitos.