First off, I absolutely adore Julian. I cried my eyes out when I first read it and I still cried through every re-read and probably will for every future re-read.
So it may come to a shock to you, and I think I’m the only one who feels this way but…
Julian needed to die.
He played the three games with Jenny and every time she chose Tom over him. He finally accepted that but if Jenny ran away before his elders took over, I think that Julian would stayed in Niflheim, constantly watching her, his jealousy and despair gnawing at him. He would either be completely wallowing in self-pity or have gone mad and just kidnapped Jenny like he always threatened to do. Her friends and Tom would obviously be very upset, Jenny would be angry and miserable living in a cold world without her friends and family and being held captive against her will and Julian wouldn’t have any happiness in knowing he is making Jenny suffer. So I believe the end of the book was the best possible ending for all the characters.
Since it’s also a YA book, Jenny wouldn’t make much of a role model giving in to the gorgeous other-worldy guy and getting everything she ever wanted without having to work for it; on top of abandoning her friends and family too. I think the ending is best left the way it is.
I understand any disagreements, I mean that’s what a forum is for and I’m very interested in reading them but if I get a rabid fan that says “OMG liek, ur not a truu Julian fan if u want him 2 die!!!111” I will seriously hit you with a wet salmon.