The Astral Walker

A concept for a demiplane based dungeon with an astral dreadnought, a merciless tank floating through the astral plane defending the portals to the god's realms by intercepting astral travellers. This is the base of the great elven sorcerer who when reaching the peak of his natural gifts managed to bargain with a high priestess of the drow to make contact with the ether. There he made a pact with a floating spirit, who granted him magical abilities beyond those given of his birth, granting long life beyond even the years of an elf, and the might of the astral void. Inside the depths of an astral dreadnought is a large cavenous demiplane filled with the corpses of dead travellers and other strange creatures. The plane has gravity and breathable, and the mage has built up over the years, creating a fortress within a fortress. Knowing the creature is mortal, this is not the forever fortress means this is surely not the end.

Structure

Exposition

The researchers of the high chapel became independent from the empire following a great betrayal. Whilst shifting their materials from the depths of the libraries, an apprentice scribe from the early research notes from the elven mage on the matter of the natural limits of a sorcerer and how his powers were peaking. He theorised different options, such as learning from the wandering bards of the eastern assembly, studying with the stowaways of the the ruins to become a wizard, or to try lesser magic such as the clerics, paladins or other. Fearing the end of his life fast approaching, he turned to an old manual laying out the various great forces known to lend magical power, and found that most providers would eventually ask for a payback cost of the highest magnitude, all except the magic wielders of the astral plane, who do not want or think and have no great plans. It presented the greatest risk and difficulty in negotiating and yet the greatest reward. He reasoned that no mage of the realms would mediate a bargaining and so turned to those of a criminal or cult nature, after various unsuccessful bargains, he turned to the under dark. In return for stealing a manuscript on the abomination of a shamoosh, the priestess created a grand ritual to beam him into the astral plane, upon which the research ends.
The party is sent to follow the bread crumb trail that lead to the great bargaining, and to find some way to stop the plans set in motion.
The mage reached assendency and attempted to carve a kingdom between the planes of exsistence and to rule all in a bid to find the secrets of creation and create a new multiverse to rule himself, with the aspiration of returning to challenge the gods of old and become the supreme being. His power lays not within his own abilities and spells, but with the allies and extensive knowledge he possesses, making any direct challenge almost impossible,
Stopping the mage is a matter of saving creation from enslavement.
The plan of the council of mages is attempt to sever the bond between the astral spirits and the mage, weaking his magical resolve.

Conflict

The Astral entity is a seeker of lost knowledge, a being beyond normality and reason, who floats through the astral planes searching for meaning. It has no set form, and looks almost as a shooting star, or sometimes as a cloud of mist. The elven mage was able to form a pact with the entity by using a magical ritual to show potential futures, one the same, one good and one evil, and within each was an infinite realm of possibility. The aim of the gifting is unclear but seems to be tied to the entity and fate.