Local man spends life studying Allag out of curiousity of ties to his family.
Loves adventure and meets his inspiration.
Sacrifices self to save world not long after meeting hero.
Spends hundreds of years in two post-apocalyptic, forsaken worlds.
Literally uses his own blood and kills self for sake of all.
Trusts his life in hands of his hero.
Actually has a happy ending and able to live life.

Can we just stop for a second and consider how absolutely batshit this character is? It's not that he has had significant character development (the whole point is that he's the same mischievous, youthful person after the centuries), but this character had gone through an experience which would typically break people emotionally, physically, and spiritually... and he came out of all of it chipper than a sparrow ready for the next adventure.

What's ultimately surprising about G'raha Tia is that he got his wish. I'm perfectly fine with him not being deep. Being deep isn't what makes characters good, it's their actions and how they affect others.