when saphira said that Arya's father, Evander, was killed by either a Forsworn or Galbatorix and that they were circles within circles, i pondered it for a while...

it occured to me that if Evander was killed by a Forsworn, then Brom, an elf, or another Rider killed him, and then they were killed by the Ra'zac or another Forsworn, etc., then it really is a bunch of circles within circles.

it also occured to me that if Evander was killed by Galbatorix himself, and Eragon killed him, then some other assassin killed Eragon, then it would, again, be circles within circles.

this is just an idea

Good point, BUT that this point I do not think that Eragon will kill Gilby alone. A 1 on 1 match

If Eragon somehow does defeat Galby then how is an assassin supposed to kill Eragon for that manner that assassin would probably be able to kill Galby first. So Eragon would have never have killed Galby and both of them might die in the end.

very smart comment club and i do beilieve eragon shall fight galby 1 on 1 (either after killing murtagh or having murtagh turn on galby thru some lupole*no idea if its spelled right*in the ancient language
because,as almost all heroes,eragons a glory hog

examples of that:in book I eragon fight the two urgals instead of telling saphira to come kill them,and later in that book he doesnt kill the urgals he just harms them.

and because i think it wouldnt be as cool if eragon didnt 1 on 1 him

Yeah... I don't think Eragon could do it by himself- Galby is too powerful.