Niruin is originally from Valenwood, where he worked at his father's winery. As Niruin explains, he was wealthy, had many friends, and was betrothed to a beautiful woman. However, he found himself growing increasingly bored with his life. He secretly fell in with a gang called the Silver Crescents, but his father found out and gave him an ultimatum; leave Valenwood or go to jail. Niruin, who had made contact with Delvin Mallory while working with the Silver Crescents, asked to join the Guild and moved to Skyrim.
Niruin can be found within the Cistern after the Dragonborn has joined the Thieves Guild.
- Like many Bosmer in Skyrim, Niruin never mentions the Thalmor or the Aldmeri Dominion, despite growing up in Valenwood.
- As heard in a conversation with Rune, he wants to start a brothel.
- While Niruin is practicing his marksmanship in the Thieves Guild's practice room, an unlimited number of arrows can be farmed by plucking them off the archery targets. The type of arrow he fires seems to be determined by the random leveled lists, but the arrow type remains constant for the rest of the game. In addition, any type of arrows can be reverse-pickpocketed on him, and he will use that type for the rest of the game.
- He may also possibly become a part of a Companions quest Rescue Mission, where the Dragonborn must rescue him from a radiant location.
- Niruin is voiced by the same actor who also voiced Savos Aren, Revyn Sadri, and some other characters.