The few times that Saphira has used magic she has specifically made the point that she had no control over the sudden ability. She has done incredible things when she has done magic (ie. Brom's tomb, star sapphire), so she logically needs a ton of energy to do that. Being a gem, is is possible that she unknowingly filled Isidar Mithrim with energy when she healed it, which was beyond her control? If so, could Eragon access this magnificent energy source and have it transmitted to him?

He could transfer it to other gems but only as much as these other gems could hold. He could also transfer as much energy as possible to himself but there will be a point which he can absorb no more. He won't be able to access any energy left in the gem if he is in another location like in Dras Leona. If he used the energy to fuel spell against the empire then the energy would be wasted because of the distance between the gem and the empire. Because of this any energy in the gem would be of limited usefulness to Eragon.

He does have a fair bit of stuff to store it in, can somebody be next to it transferring it to him, so he can replace it as he uses it in a battle or something? Also, he definitly didn't fill up all of the current stuff he had, so anything would be an improvement.

I never quite thought of this idea, though it does seem completely believable, you have a broad imagination, I like that

i never thought of that either but think of all the power you can hold in it if you had the dwarf and varden and elfs transfer energy into it once a month you could complatly distroy galby and his servants and his castle and if it is enough then you could maby bring someone back to life because they need all that energy to heal the wound get healthy and the time they missed



Eragon coudd bring Brom and oromis and gladur back with it and maby broms dragon and still have some left over three very powerful dragons and riders against two very powerfull dragons and riders they would be unstopable



oh he could fix oromis too so he can do spells too

I don't think CP would do that(raise the dead), it would open up too many possibilities in the book, but I think that they wouldn't have put so much emphasis on the star sapphire in the 3 books if it won't be important in the last one. Apart from everybody putting energy into, its possible that saphira filled it herself with her burst of power as she fixed it.

that would make a lot of sense if there was energy in the gem. He would be able to transfer energy from the gem; just like how he gained energy from the livestock killed in book three. I don't think he will be able to bring anyone back because it would be a tremendous problem. how would you bring someone back. how will he be sure he will live to kill galby. Who would he bring back? how many could he bring back? there's too many questions and not enough answers

there is not nearly enough power in isidar mithrim to bring back the dead
and just because its huge all gems can hold infinte energy remember

Eragon might want to bring the first Eragon.