A Necromancer Altar is required to convert a Grand Soul Gem into a Black Soul Gem. One of these altars may only be used once a week on a certain night of the week. On the night when one may be used, it will be illuminated by a purple beam of light shooting downward from the sky (see Gallery). This beam of light is more noticeable further away from the altar; if the player is standing directly in front of the altar, it is easy to miss; however, if there is a Necromancer present, then it is most likely the right day (correct days end at midnight).
Necromancer Altars are located at the following locations:
- The grand soul gem that will be used at the altar must be empty or one filled by the player — a grand soul gem that is found or bought with a soul in it will not work. (The new black soul gem will be empty, so don't use soul gems with a grand soul already inside, that way the grand soul won't be wasted). The player may hit the altar with a touch- or range-based soul trap spell (for a lower class character or non magic user, touch is more accessible, as it requires much less magicka, is cheaper to purchase, and does not require a high mysticism skill level).
- Azura's Star does not successfully turn into a black soul gem.
- The altar is active from midnight to midnight on the active day.
- Each altar is only active on a particular day of the week. The specific days vary from game to game (or in some games it may be completely random). Starting at day 1, when the player exits the Prison Sewers, and every eight days thereafter for a 24-hour period, the event will occur.
- The player may determine when an altar is active since it occurs every multiple of 8, then add 1 day. For example, if the player is on day 72 (8x9), the altar is active on the following day, day 73.
Using a Necromancer AltarEdit
To use a Necromancer Altar, the player must put the empty Grand Soul Gems that he/she wishes to convert into the altar on a night when the altar is active. Then the player must close the altar and cast a Soul Trap spell on the altar to convert one of the Grand Soul Gems into a Black Soul Gem. This process is repeatable — cast Soul Trap as many times as there are Grand Soul Gems to convert. (See the Gallery for the before and after displays). The player should also be careful of other Necromancers that may be using the Altar.