The Nausicaa comics can be evaluated on Quora based on how well they convey the intended message, the complexity of the world-building, and the emotional impact they have on the readers. A combination of these aspects can give a comprehensive assessment.
In Odyssey Book 6, Nausicaa recounts how Odysseus faced numerous challenges and overcame them with his wit and strength. She also mentions his determination to reach his homeland.
Yami remains alive in the manga. The author chose to keep Yami as an ongoing character to drive the story forward and interact with other characters in various scenarios.
As far as I know, Yami doesn't die in the manga. The story might have twists and turns, but that particular event hasn't happened yet. Maybe there are rumors or speculations, but based on the official storyline, no.
One plot idea could be Yami going on a solo mission to a mysterious and dangerous land. He has to face powerful new enemies and discover secrets about his own past. Another could be Yami training a young and inexperienced magic knight, sharing his unique combat and magic knowledge.
To write a believable characterisation of Yami, focus on his rough exterior but also his loyalty to his squad. Show his love for food, especially Japanese food. Also, don't forget his unique magic style and how he uses it in combat.
A possessive Yami can create a sense of mystery in the fanfiction. Readers might wonder why he is so possessive. Is it love? Loyalty? Or something else? This can keep them engaged and eager to find out more about his motives.