Aldanon was a wealthy, yet absent-minded, sage living in Neverwinter. Originally, he built his manse on the outskirts, away from the main thoroughfare, but the reconstruction following the war with Luskan in 1372 DR resulted in his home being in the middle of the new Blacklake district. As such, he began placing wards in order to keep out opportunistic nobles hoping to buy his estate, as well as the murderer on the loose in 1374 DR.
Aldanon had came into the possession of one of the silver shards from the Sword of Gith, though he had long since forgotten who sold it to him. He knew Ammon Jerro from long ago, when he was a court wizard at Castle Never, and knew that Jerro had once possessed a githyanki silver sword (though not that it was Gith's own blade).
When the Kalach-Cha and companions arrived in Neverwinter with a shard, they had Sand examine both that and Duncan's shard, detecting the two had far more power than before. Determining this was beyond his skill, Sand suggested the Kalach-Cha take it to Aldanon for a more professional analysis. Unfortunately, the murders of Dalren and other noblemen led to the Blacklake district being quarantined, forcing the Kalach-Cha to work through the City Watch or Shadow Thieves to get access. After obtaining access, the Kalach-Cha was able to visit Aldanon in his manse. The sage was interested in the two shards, allowing him to compare them to the one he had. After a quick test, he finally determined they were pieces of a githyanki silver sword.
Aldanon knew about the githyanki Sword Stalkers, and that they searched for missing silver swords. He believed that was why they were seeking out the Kalach-Cha and the shards. He knew that Ammon Jerro was more knowledgeable on the subject, but was told he had died long ago, and any research of his would likely be kept in his Haven. He recommended the Kalach-Cha visit the Neverwinter Archives and try to find any information on Jerro, or his family, that could lead to the Haven.
Later, he learned that Lord Tavorick had possession of another silver shard that had been passed around by nobles, and believed that might have been what the Blacklake murderer was trying to find. He sent a message to the Sunken Flagon, but by the time the Kalach-Cha arrived, the house had been taken over by several thugs and Aldanon was missing. Aldanon found himself in Crossroad Keep as a prisoner, and learned from fellow prisoner Zhjaeve that Black Garius had abducted him because of difficulties in deciphering the Tome of Iltkazar. Aldanon remained relatively oblivious of the situation, and became entrenched in the many tomes stored at the keep. Among the rare books Garius and the Arcane Brotherhood had at the keep was a copy of the Tome of Vile Darkness, which Aldanon later noted.
The Kalach-Cha met him again in the (ruined) library after sneaking in through the escape tunnel. Aldanon was still oblivious to Garius's activities, and was far more interested in reading the tomes. The Kalach-Cha commanded him to flee to Neverwinter and warn the city of the possible danger, but not before Aldanon commented that if they started their "dark rituals" the best way to stop them was to make a lot of noise. As the Kalach-Cha stormed the ritual chamber, they lost focus and Garius and his ritualists were destroyed in the shadow backlash. The Greycloaks rescued Zhjaeve from her cell and Lord Nasher granted the keep's control over to the Kalach-Cha.
Back in Neverwinter, at Captain Brelaina's office, Aldanon (confusingly) tried to explain who and what Zhjaeve was to the captain. Brelaina gave up and instead suggested the Kalach-Cha handle it, as the prisoner had specifically requested the Kalach-Cha himself/herself. Aldanon however was anxious to return to the keep and examine the contents of the library there. Once the library was fully refurbished by the Kalach-Cha or Nasher Alagondar, he relocated there for the remainder of the struggle.
Aldanon suspected the shadow tide emerging from the Mere of Dead Men was just an outline, and only strongest at its outer edge. He theorized they could safely strike at the King of Shadows if they could somehow teleport past the shadow barrier and into the heart of Merdelain. He thought the Tome of Iltkazar may have such a means in it, which the Kalach-Cha eventually retrieved from a Shadow Reaver. As the siege of Crossroad Keep raged on, Aldanon searched through the tome. He eventually determined a means to teleport the Kalach-Cha and companions directly into the Vale of Merdelain. With this, the party was able to reach the final dungeon where Black Garius and the King of Shadows were located.
Aldanon was very absent-minded but easily distracted, never able to stay in one place or examine one thing for very long. He fidgeted constantly, whether cracking his knuckles, tapping his foot, or shuffling about.
Aldanon was voiced by Milton James, who also voiced Cyran.