Dialon, the Spirit of Determination, was the alter ego of Diablo, and was worshiped by members of the Cult of Dialon, a part of the Triune. Dialon was represented by a stubborn ram.

The Cult of Dialon was led by Arihan, and existed several hundred years before the events of Diablo I. The shattering of the Triune during the Sin War made the Cult of Dialon be forgotten. It is speculated that, with the resurgence of the Triune in Diablo III, Dialon worship is again practiced in Sanctuary.