Dark Nebula (location)

Dark Nebulae (暗黒星雲 Ankoku Seiun) are interstellar clouds so dense, not even light can get through, hence why they appear to be dark. It takes special equipment or a lot of power to enter or leave the nebula, which makes it a great place to stick things you really don't want roaming the vastness of space.

Victory cartoon
500,000 years ago, Deathsaurus built his Planet-Destroying Fortress in a bid to become the next Emperor of Destruction. When this information reached the Autobots, they moved out under command of Star Saber to get the weapon out of the Decepticons' grasp. Rather than destroying it, they locked the fortress in a gravity cell, draining the energy out of it and steering it straight into the Dark Nebula.

After somehow escaping the Nebula and developing a magnetic field to allow him to move freely through the gravity well, Deathsaurus spent the next several millennia searching for enough energy to reactivate and free his fortress from the Dark Nebula. After such a long imprisonment, however, he grew doubtful the Planet-Destroying Fortress could still be revived, so he and the Dinoforce flew the Thunder Arrow into the Dark Nebula, with a good amount of energy in its hold. With the energy, the fortress was briefly brought online, assuring Deathsaurus his efforts weren't for naught. Increasing his efforts to obtain the required amount of energy, he and the Breastforce were finally able to get the fortress up and running, after which it flew out of the Dark Nebula.

Return of Convoy
From the Dark Nebula, Dark Nova observed with glee how his troops were raiding the Earth of its energy.

Animated cartoon
The Dark Nebula was a region of space in the Milky Way. It contained Vhoorl and the destroyed Zarak.

Wings Universe
While near the Dark Nebula and on the way to investigate a Predacon colony, Primal Prime's crew of Wreckers on board the Rodimus Major disappeared into a spatial anomaly.

Ask Vector Prime
Vector Prime noted that iterations of the Dark Nebula originally had a tainted world at its heart.

In Viron 102.0 Beta, the Elite Guard evaded the Elder Gods in the Dark Nebula.

In some Primax reality, Devil Z resided in the Dark Nebula. It was there that Stealth Bomber and Scoutjet met with the entity to plead their master Devil Gigatron's case. Apparently they succeeded as Devil Z upgraded Gigatron into Gigatron Z.