Board Thread:Lore Discussion/@comment-29592846-20160811185601/@comment-30400956-20161207035603

Vivec ceased to hold up the Ministry of Truth because of the rise of the Reclamations and the end of the Worship of the "False Tribunal". The stipulation for Vivec preventing Baar Dau from plummeting to the surface of Nirn was that Vivec would hold it up as long as the Dunmer people loved him, as his action was one of love.

CHIM, at its most basic, does technically allow one do anything within the Aurbis, such as prevent a meteor from crashing,  change the landcape of an entire region, or kill a Daedric Prince's manifestation on Nirn, it always carries the risk of waking the Godhead, which is why it is used so sparingly.

Vivec's ability to rewrite his own history as to have been born a god is due to him taking advantage of the Dragon Break which occured at the Battle of Red Mountain, which surrounds the events of the Disappearance of the Dwemer and the Godhood of the Tribunal. Because a Dragon Break encompasses a period of nonlinear time, any account on the events during a Dragon Break are as valid as another, meaning Vivec's account recorded in the 36 Sermons is as true as what we are led to believe had happened.

As for CHIM and immortality, the answer isn't really clear. The only Two individuals known to have achieved CHIM both gained a form of immortality, Vivec by using The Heart of Lorkhan, and Tiber Septim by mantling Lorkhan, which could be connected to the fact that Lorkhan was the first being to attempt CHIM, and the only one to have intentionally failed to achieve it.