Tet

Tet is the One True God of Disboard, a title he claimed after the Great War by obtaining a relic called the Suniaster before any rival god could reach it — despite, by his own account, sitting out most of the fighting entirely. It was Tet who wrote the Ten Covenants that ended the war and now govern the whole world, banning violence and forcing every conflict, down to national borders, to be settled through games instead.

For six thousand years undefeated, he spends his immortality wandering Disboard in disguise, hunting for opponents interesting enough to hold his attention, until an online chess match against two human siblings finally ends his winning streak. Delighted rather than humbled, he pulls Sora and Shiro into his world and offers them a way to challenge him directly for his throne: unite or defeat all sixteen races first.

Despite ruling over reality itself, Tet behaves like an overgrown child — cheerful, mischievous and openly bored by the other gods, whom he considers far less fun than mortals. He keeps a particular fondness for the werebeast girl Izuna Hatsuse, whom he once challenged to games after she found him fainted from hunger on the street, having forgotten, mid-disguise, to eat for three days.