From deity "Description:"
The entity known as Aadu has many guises, which is not surprising given its chaotic nature, but it is usually depicted as “the Maelstrom ”: a large, swirling mass of ooze and foul wind from which tentacles, pseudopods, eyestalks and other writhing extensions emerge. Aadu is truly mad and in his madness seeks to undo the whole of Creation. Those who serve it, usually suffering from insanity themselves, believe themselves to be its divine instruments, destined for reward in whatever afterlife the Destroyer may offer.
Aadu’s realm is a vast, swirling maelstrom in the center of the Sea of Ichor, a large body of water found in Gehennim . The Lord of Madness has merged his essence with the watery vortex, drawing all who venture too close into his domain of destruction and chaos.