Just figured I'd add this in here before taking something of a break for a few days. It's from the Ravenloft DMG and it goes roughly:
Ascended Outsider's: When a mortal's creature type permanently changes to "outsider" (such as a 20th level Monk), the character is said to have ascended. A NON-Neutral ascended outsider gains the type descriptors (Chaotic, Evil, Good, Lawful) matching it's ethical and moral alignment. A lawful Evil Monk, would gain the Evil and Lawful descriptors, for example, and would thus, be considered a Fiend. The reality wrinkles for Ascended fiends and Celestials, are half the radius (1,000 feet per HD) of those emitted by outsiders that were never mortal.
Native Outsider's: Outsiders that were spawned within Ravenloft itself (such as most Ascended PCs) do not gain phylacteries;
if destroyed their spiritual essence disperses into the mists.The Mists Descriptor: When a hero ascends to become and outsider within Ravenloft, she can take the Mists Descriptor if she wishes to (see Ravenloft Players handbook, Chapter Three, "Altered Majic" Conjuration). In terms that would concern a PC, such outsiders can pass through any closed domain border without harm, but they do not gain reality wrinkles, they can not perform power rituals, and they can never leave the realm of dread. Indeed they are literally an extension of the mists.
Note taking that can be pretty funny when Azalin Rex or Strahd summons something with the Mist Descriptor, and Brother Maynard shows up.
~Rex