Numidium

First Numidium (Anumidium)
The Numidium was constructed by Dwemer artisans during the First Era, and was intended to serve as a god of sorts for the Dwemer people. There are many theories that propose that it was built to allow for the mortal plane's transcendence. The original power source was the Heart of Lorkhan, whose power the Dwemer had accessed using Kagrenac's Tools: Keening, Sunder, and Wraithguard. It was first used in the Battle of Red Mountain, when Chimer forces assailed the Dwemer stronghold and captured it after the mysterious disappearance of the Dwemer.

The Numidium was gifted to Tiber Septim by the Tribunal in return for Morrowind's semi-autonomy. The Emperor ordered his Imperial Battlemage, Zurin Arctus, to construct a control device known as the Totem of Tiber Septim. The Tribunal did not include the Heart as a power source, so a new one called the Mantella was created and infused with powerful life energy.

The Numidium was used by Tiber Septim to subjugate all of Tamriel, including the neutral Tamrielic royal families, in an attempt to eliminate anyone not absolutely loyal to his rule. An enraged Zurin Arctus attempted to halt the Emperor's mad conquest, and in the ensuing chaos, the Totem was lost and the Numidium was shattered.

In, the Mantella is recovered, and the Numidium is activated by an unknown person. As a result, a "Dragon Break" (a spacetime anomaly) occurs. Subsequently, multiple endings of Daggerfall occur simultaneously: the Kings of Iliac Bay are defeated, preventing a major war; Orcs become citizens of the Empire; the King of Worms becomes a god; the Underking dies, and The Hero of Daggerfall is slain. The Numidium completely disappears as a result.

Second Numidium (Akulakhan)
The second Numidium (named Akulakhan) is a partial reconstruction of the first Numidium; as detailed near the end of, it is powered by the Heart of Lorkhan. Its construction was overseen by Dagoth Ur, whose goal is to cover the entirety of the world with his Blight, a deadly disease that he uses to infect, convert, and control the citizens of Morrowind, so all mortals might be connected to the Heart and thus be controlled by Dagoth Ur.

However, in 3E 427, the Nerevarine arrives in Vvardenfell from the Imperial City prison, recovers Kagrenac's Tools and leads an assault against Dagoth Ur. Using the power of the tools, the Nerevarine is able to destroy the enchantments on the Heart, killing Dagoth Ur and making Akulakhan literally fall apart, which causes it to fall into the lava below.