Thulkos began as an Assiatic dimension. Like Earth’s cosmos, Thulkos started with a Big Bang. In Thulkos, however, matter gathered into circular loops rather than spheres. Thulkos itself was a slender ring of rock, metal, water, and air 500 miles thick but more than 160,000 miles in diameter. This noodle-shaped world spun along a threadlike star 2,000 miles wide but forming a loop hundreds of millions of miles long. Thulkos shared its star-thread with several other worlds of various sizes. Some worlds were themselves ringed by doughnut-shaped moons. Millions of other stars circled in a ring-shaped galaxy over a hundred thousand light-years wide, the only galaxy in this Reality.
After he conquered Thulkos, Tyrannon reshaped his home dimension into a series of shells centered on himself. In the process, he drastically shrank Thulkos. This concentrated the dimension’s ambient magic, permitting a cosmic structure that would never work under previous natural laws. By imposing his will on such a scale, however, Tyrannon also bound himself to Thulkos' reality. Only his weakest forms can survive without some connection to Thulkos.
The very center of the dimension holds Tyrankos, the Conqueror's capital. Tyrankos is a disk 100 miles wide and seven miles thick. One side is landscaped with farmland, towns, temples to Tyrannon, and concentration camps for sacrificial victims. The Tree Throne lives at the very center of Tyrankos, so the entire dimension orbits around Tyrannon’s mightiest form. The underside of Tyrankos is bare, jagged rock. Tyrannon didn’t bother giving Tyrankos underside gravity. Ironically, the very heart of Tyrannon’s empire holds a place the Conqueror ignores.
Dozens of Thulkosian world-loops form a filigree cage around Tyrankos. The smallest worldloop is about 60,000 miles in diameter, while the largest is 150,000 miles wide. The world-loops hold bands of land and ocean, with mountains, deserts, rivers, and other landscapes like those on Earth, though many plants and animals look somewhat different. In all, the world-loops have a surface area twenty times that of Earth. Air extends from Tyrankos all the way to the outermost world-loop. Huge, magical sky-galleons fly from world to world. Their sails, painted in blood with the sign of the Avian Throne, catch astral winds created by Tyrannon for this purpose. For more rapid transportation, Tyrannon created Gates between worlds. A hundred billion people, humanoid Thulkosians and several other species live in this, the heartland of the Conqueror’s empire.
Around this shell of world-loops orbit the eight globes called the Kae Linn. These eight magical suns orbit between one to two million miles from Tyrankos. Thulkosians receive day when their part of a world-ring faces outward, toward the nearest Kae Linn, and night when they face inward to Tyrankos.
On Tyrankos itself, at least half the distant Kae Linn are in the sky at all times, so Tyrannon’s capital receives a dim but constant daylight.
Tyrannon created the Kae Linn by magic and each orb imprisons a god of sunlight, fertility, and healing. Releasing these gods, who are also called the Kae Linn, would snuff the eight suns and doom billions of Thulkosians to freezing death.
Beyond the Kae Linn lies a second and greater shell, but this is a shell of star-threads. These loops of glowing gas are thousands of miles thick and hundreds of millions of miles wide. The largest are a billion miles in radius. Up to a dozen world-loops of various sizes slide along each starthread.
Only one world-loop per star is habitable, though. Tyrannon moved all the worlds settled by Thulkosian humans to the core shell of worlds, along with the homeworlds of the other sentient races in his cosmos. The second shell received the aliens colony worlds, and most of the other habitable worlds Tyrannon found within his galaxy.
Trillions of people, from many species, live in this second shell.
A tenth of a light-year from Tyrankos, the third layer begins. Thousands of star-threads, many with world-loops, orbit the dimension’s core in a vast smoke-ring of stars. This smoke ring extends outward two light-years, becoming sparser with greater distance from the core. These thousands of stars are all that remain of the rest of Thulkos’s galaxy: Tyrannon destroyed every star-thread that was too small or faint to support a life-bearing world, since he didn’t want billions of ‘useless’ stars and planets in his universe. The Conqueror once planned to create more habitable worlds in this outer star-ring, but he now sees the conquest of other dimensions as a quicker means to expand his rule.
Tyrannon gives a low priority to patrolling the sparesely-settled, widely-scattered worlds of this cosmic hinterland. Instead of sending Emissaries, he leaves the job of managing these frontier worlds to merely mortal servants and soldiers. Anyone who can escape to the star-ring can easily pass beyond the reach of the Thousand-Headed God, so long as Tyrannon does not think they are important.
Beyond the intensely magical core of Thulkos, however, the star-threads orbit in vacuum, so a traveler between worlds needs some form of magical transportation, such as a Gate.
Beyond the smoke ring, a few star-threads and sunless world-loops drift through the dark void. Most of these are just bits of Thulkos that Tyrannon missed when he reconstructed the universe.
Some, however, hold gods imprisoned by Tyrannon or hiding from him, both protected and isolated by light-years of empty space. Exiled gods create small environments to suit themselves. Gods in hiding might even collect small communities of worshippers through raids into the hinterlands of Thulkos. The exiles hate Tyrannon... but that doesn’t necessarily make them better than him.