Death: So I am a Quincy

(No system, not a single female lead, not a Long Aotian-style protagonist)
I came to the world of death for no apparent reason. Huh? Why do I start as a spirit?
After entering Soul Society and practicing hard to reach the Shikai, Amemiya looked at the bow and arrows formed by the clustered spirit particles in his hand and fell into deep thought.
Why does this Zanpakutō seem more and more wrong the more I look at it?
……
"Hastwald, I have seen the future..."
"Quincy, Shinigami, Fullbring, Hollow. My son, Amamiya Tsutomu... You will be resurrected as a Holy Son and slay the Soul King for me!"