longer wished to continue living. Vrael however, encouraged Thuviel to sacrifice himself by turning his body into pure energy. Galbatorix long believed the eggs hidden within the Vault of Souls to have been destroyed in the explosion. Thuviel's sacrifice made Doru Areba uninhabitable for even hundreds of years afterward, akin to the effects of nuclear radiation. Dragons In the books, the dragons are grouped into those bonded to Riders and wild dragons. The wild dragons are far more fierce, while the bonded dragons are more intellectual. All dragons hatch from eggs, in which they can remain for a very long time; once hatched they have a nearly infinite lifespan and continue growing their whole lives. They can breathe fire and reproduce at about six months old. When a dragon dies, it has the option to transfer its consciousness into a diamond-like organ inside its body called an Eldunarí. If it disgorges its "heart of hearts" before its death, the dragon has no choice but to retreat into it when it dies. Such Eldunarí will live on until another creature destroys them. Dragons are a variety of colors, which do not appear to be related to their parents' colors. Glaedr is the gold dragon bonded to Oromis. He is at least three times as large as Saphira and a skilled fighter, but lost his left foreleg in battle with Formora. After escaping the Forsworn, Glaedr and Oromis went into hiding in Du Weldenvarden to teach the first of the new generation of Riders. He disgorges his Eldunarí shortly before his and Oromis's death in Brisingr, and is thus forced to live on after his body dies. Thorn is a red male dragon bound to Murtagh. He has been magically grown to large proportions, but still has the mind of a child. Saphira refers to him as "Red-Shrike-Thorn". Shruikan is Galbatorix's black dragon, the largest of all the dragons to appear in the series. He was twisted into the king's service through black magic. The dragon's name is a play on the word "shuriken". Jarnunvösk was Galbatorix's first dragon, who was royal purple. She was killed by Urgals (deceased, pre-series). Saphira is a female dragon bound to Eragon and a central character of the series. Eragon first encountered her as an egg (believing her to be a rare stone) while hunting in the wilderness of the Spine Mountains early in the first