"Then, when all seems lost, go to the Rock of Kuthian and speak your name to open the Vault of Souls..." ~Solembum, in Eragon
The theory is short and to the point, but yet still of massive proportions. Check it out.
The Varden is defeated and destroyed, but Eragon and Saphira live, thus all hope gone for Eragon. Somehow, Murtagh changes his true name and escapes Galbatorix's clutches. Before he leaves Galbatorix however, he steals the green egg. He gives it to Arya, to whom the egg hatches. Then, the task of defeating Galbatorix would lie to the three remaining dragon riders. This would be the ultimate redemption: as Galbatorix rose to power by defeating the Riders, it would be the Riders task and the Riders task alone to defeat Galbatorix. Of course, dragons would want revenge also, so eldunari that Eragon gets from the Vault of Souls would be distributed among Eragon, Arya, and Murtagh so that they would have the souls of dragons helping them defeat Galbatorix. To set Eragon apart as the head Rider, he would have a new power gained from Tenga: the ability to harvest energy from light and/or fire. So, with his sword, Brisingr, he could call upon fire and hence have an unlimited supply of energy coming from Brisingr. Then, of course, Eragon, Murtagh, and Arya would defeat Galbatorix.
Any thoughts? I left this blog open to comments, unlike my other blog.