Elyon is the name of God in the Other Earth.
Elyon created Other Earth as well as the Earth in the Histories.
Elyon seems to take no direct form, lion, lamb, child, man. He is a loving God and cherishes his people as well as his Roush.
All though he hates no one in the series, he does have an enemy, Teeleh. Teeleh seems to mimic a corrupted version of whatever Elyon creates.
For example Elyon has a Colored Forest and Teeleh has a Black Forest. Elyon has green waters and Teeleh has black waters.
Although he is despised by the horde he wishes his people to love the Horde for him
In the Series becoming one of his people involves his sacred lakes.
His laws of becoming one of his people has changed over the years. As in the start to remain without disease all you had to do was to bathe in the Green lakes, but later in the series his son Justin is sacrificed and all the lakes turn to blood. Now to become one of his people permanently all that is required is to drown in one of the red lakes.