You can kill one character in the EU at any time in the timeline you want. Maybe you think characterx should have died during LOTF and you wanted them to die in NJO or maybe you thought Jaina Solo should have died in YJK, the choice is yours! Personally I would've had Boba Fett die during TUF in a blaze of glory. Or alternatively I would've liked to have seen Zekk die by Jacen's hand during the last third of LOTF. Makes Jaina angry and would have been cool since Zekk was always the one during Star By Star and Dark Journey worrying about the Solo's going over to the dark side.