|This article is about a non-canonical topic in the Metal Gear series.|
The Lord of Dust was a creature composed of Dread Dust, an advanced, self-replicating form of medical nanomachines, that ravaged the world by the 22nd century, and used wormholes generated from Kuban and Iris energy to go back in time and start the process of assimilating and devouring the world over. It repeated the process again and again, becoming more powerful each time. Goodluck sent the Captain to Dite to kill the Lord of Dust at its weakest state.
The Captain succeeded in shooting the Lord of Dust with Metal Gear Sahelanthropus' rail gun. However, it only reassembled itself as it had no concept of death. Virgil AT-9 nearly sacrificed itself to introduce the concept of death to the Lord of Dust, and the Captain fired at it again with the rail gun, killing it.
Behind the scenes
The backstory of the Lord of Dust, and by extension, the Dread Dust and all byproducts of it such as the Wanderers, is a reference to various apocalyptic theories, including especially the concept of grey goo.