Vampire Intelligence

The Vampire Intelligences are a eldritch vampiric race of sadistic and malevolent alien intelligences, interdimensional conquerors and rivals of the Splugorth. Their horrifying eldritch form consists of a lump of slime covered flesh with a huge cyclopean eye surrounded with a hundred smaller eyes. The body itself can reach up to 200 ft in diameter. A dozen tentacles ending in fanged mouths protrude from the flesh and are able to stretch up to 200 ft. They are vampiric beings which live off of a world's magical energy and enjoy feeding on the blood of humanoids.

They are incredibly strong and are able to regenerate, even capable of surviving a 1.2 megaton nuke, though not without taking grievous wounds. Vampire Intelligences have formidable psionic abilities and are able to wield magic. As a supernatural entity it is vulnerable to weapons of wood or silver, and both holy and running water all of which can do more damage than conventional and energy weapons.

Vampire Intelligences can send fragments of their essence into other dimensions, bonding with willing hosts with whom they are able to communicate. Once it is in possession of a host, the lifeforce shard fragments further into thousands of tiny pieces which are used to create vampires. A Vampire Intelligence is able to physically enter and inhabit a dimension once a few thousand vampires are created. It then seizes control of a magical nexus (ley lines) which permits it to maintain a physical presence in that dimension. A fortress is then built at the location to prevent its use by inter-dimensional travelers or other magical users. As long as its in that dimension, the Vampire Intelligence is linked to all the vampires which its lifeforce created, up to several miles from its location. Several of them have established strongholds in the future post-apocalyptic Earth, most of them in what used to be Mexico, domains known as the Vampire Kingdoms.

Trivia

 * They resemble some of the conventional conceptualizations of "Old Ones" and the Shoggoth.