He was one of the three sons from the Gauldur family who was killed and expunged from the history books in the quest "Forbidden Legend." He took part in killing his father, Archmage Gauldur, and holds one third of the amulet that he and his brothers stole and split.
Sigdis is a very powerful draugr. He carries the Gauldur Blackbow, which absorbs a level-dependent amount of points of magicka per hit. He also knows the Unrelenting Force and Disarm shouts, and he teleports when he has been hit a few times, as well as creating clones of himself to trick opponents into wasting their attacks. An easy way to tell which is the real Sigdis is to target them. The real Sigdis will show damage if he has been injured, where as the clones will always have full health. If a clone is attacked, it will automatically disappear. Alternatively, in the first battle Sigdis will not glow as much as the clones do, while in the second battle he will also wear a different helmet from them. When he dies, he will have the weapon Gauldur Blackbow, a Gauldur Amulet Fragment (stamina version), and a Writ of Sealing, along with some arrows and sometimes minor loot. As he and his clones use Unrelenting Force frequently, it is hard to use melee attacks on them. This can be slowed by the use of follower who can help with fighting the clones and detecting who the real Sigdis is. The real Sigdis wears an Ancient Nord Helmet, whereas the clones wear the same helmet as Jyrik and Mikrul Gauldurson.
- Sigdis is the only Gauldurson Family member able to use all three words of the Unrelenting Force shout, and is the only family member able to use Disarm.
- His tomb is the only one not to feature a Word Wall, meaning there are no available Words of Power to learn there.
- His Unrelenting Force can ragdoll the player, as it is identical to the full power version used by the Last Dragonborn. This makes the battle against him even harder, as he will continuously try to incapacitate and disarm the Dragonborn.
This section contains bugs related to Sigdis Gauldurson. Before adding a bug to this list, consider the following:
- If Sigdis is killed by the damage from a damage over time effect (from weapon enchantments or the Flames spell), or finished off with a finishing move, or from being backstabbed from sneak just before he teleports away, his corpse disappears, thus making him unable to be looted.
- This may be fixed by exiting Geirmund's Hall and re-entering.
- If Unrelenting Force is used on him just as he teleports, he will reappear laying down, impervious to all melee and ranged damage. Magic attacks will still injure him. Using Unrelenting Force again will fix this.
- Paralyzing Sigdis and allowing the stand up animation to start just before teleporting will cause him to teleport standing still. He will be unable to attack as a result.
- If positioned just right, Sigdis is able to shout the Dragonborn into one of the staircases on the towers. Once he shouts again, he will fire them out of the staircase if the shout is positioned right.