The Miasma is an item found in The Elder Scrolls Online. The Miasma is a purplish gas, produced by the Skull of Corruption and used by the priests of Vaermina. Any mortal exposed to it will fall into a deep sleep, which slows the aging process and can last for extended periods of time. A long sleep under the Miasma can cause brain damage, and some victims lose their mind entirely.
This item can be found in the following locations:
In the quest "Thalmor Rising," various Altmer in Thalmor garb are seen in Dreamstride Cove, apparently affected by the excess Miasma they were using to create a new, Miasma-affected blade called the Trance Cutlass for the Aldmeri Dominion. In the quest, The Vestige must purge the cove and retrieve the unique weapon and return it to a Priest of Vaermina in a radiant location.