Dungeon Lings

Viking Souls stolen from Valhalla by the Necroking. 
Put through an extraplanar spell requiring the tome of the skyempires magus, a crystal from the illithid plane, a soul willing to fight, a mithril shackle inlaid with spell runes, and dwarf blood.
Dwarf blood is placed in the runes to activate the spell. The mithril is etched in dwarvish with the words "Return to fight lost soul from beyond".
When born they tear a black veil between this world and the illithids outer planes. Tenticle horrors will come out over time. The Dungeon Ling leaves this black veil in its wake wherever it walks.