Devils Explained: The Underworld and the Tree of Qliphoth

Devils are ranked by power into low, mid, high, and supreme tiers, all ruled by a single king of devils. The higher a devil ranks, the more magic power it commands and the more gates it must cross to reach the living world.

Zagred, the Word Soul devil who orchestrated the elf massacre, is the most powerful devil to fully manifest in the story so far — bending reality itself to his cruel whims. Most devils, however, can only reach the living world through a host.

The Underworld and the human world are separated by the Tree of Qliphoth — a structure of gates that devils must force open to manifest fully. The Dark Triad of the Spade Kingdom sought to open all the gates at once to unleash the king of devils upon the living.

Because crossing these gates strips away most of a devil's power, even the strongest devils usually possess humans or form pacts rather than appearing directly. The Dark Triad — Dante, Zenon and Vanica — each fought as a vessel for the devil power housed within them.

A human can form a pact with a devil to borrow its power. Nacht Faust commands several devils at once, including the shadow devil Gimodelo, while Asta shares a unique bond with Liebe, whose Anti-Magic sets him apart from every other devil.

These unions are double-edged: greater power demands a greater toll, and a careless contract can let the devil seize control of its host entirely.