These monstrous demons can weigh in as much as 15 tons at 120ft. They can have many different colors, but they all share a blue luminescence that is displayed on their limbs. Overseer demons are the evolved and sentient form of gurud demons.
Young overseer demons seclude themselves so they can gain strength and power. Sometimes, they will form packs from dire gurud that swarm the hellscape. Centuries later, they are considered Arch Magis from demon kind, as they have grown in such strength and magical prowess. In common tongue, they are called Dragul.
Overseer demons created and perfected their own form of spell casting called Sigil craft. It is derived from the innate magic in these demons and is recognized at a young age in a burst of raw power. Sigil craft forces this power into a fine point through the use of the sigil craft alphabet and with the right combination of letters, it can unleash hell upon those unlucky enough to come across these sentient beings. Without absolute perfection when performing these spells, the blowback on the caster could be catastrophic. Masters of the craft created a shorthand that speeds up the process to deliver the magical blow onto their enemies.
For centuries, the overseers ruled hell, each carving out a territory and they managed to keep the peace amongst themselves. Secundis the Immortal changed that by hunting the Overseer demons, taking control of hell. His subordinates, the Elite Caste, nearly wiped them out. Those that survived this purge went into hiding.