I do think we have seen some of Tier's issues before in other elves. Skywise had some issues with abandonment for a while (and I quote- multiple times- "you abandoned me!")- and l'oss of mommy' trauma flashbacks (book 2). Windkin is a case study in the 'mysterious loner' category. I guess that's why Dewshine drew a parallel between him and Tier. And Cutter has experienced denied recognition. Suntop has done the whole 'Winnowil is inside my head' trip. And I know at least one or two elves have spazzed out and done their own thing, launching everyone else into trouble. So Tier isn't the first to have these issues. He just might be the fest character to have them all at once..