Board Thread:Lore Discussion/@comment-3322638-20130429120723/@comment-13446185-20140315172609

107.138.156.61 wrote: (btw how the hell does numidium cause so many breaks and only vanish after the warp?) The Numidium was an attempt to have the Dwemer as a race escape creation and return to the Dawn (or beyond), sort of like what the Thalmor are planning just alot less evil. Due to this return to Dawn and the inconsistency of its timeline, it creates Dragonbreaks.

The Warp of the West didn't have the Numidium disappear, it destroyed the Numidium. The most likely reason for this is that all the warring factions were given the Numidium, so the Numidium was probably actually fighting itself (Also the Underking was there to whoop some Numidium ass).

After Alduin was killed, he was sucked into the vortex above Sovnegarde, ending up in the dreamsleeve. Using this, he is able to reach down to Nirn and possess the dragonborn, causing a break, which he uses to shift the LDB through time on a mass8ve murder spree, and in the conclusion, Alduin vanishes from time, and the LDB is forced to flee Skyrim, letting the dragons cause havoc until he is forgotten and he returns.

That is extremely speculative. But seeing as we don't actually know what happened yet (I believe it was an Enantiomorph), I won't try and prove it wrong.