Kisenemi

In the Bleach universe, the story begins just before Ichigo Kurosaki and his friends invade Soul Society to rescue Rukia Kuchiki from execution. Kisenemi is a rare natural Arrancar, born without Hogyoku intervention, wielding a shortened nodachi with a red hilt and a black light-absorbing blade. His Espada-level power led him to reject Aizen's army, drawing enmity from Soul Society—who view him as a dangerous anomaly—and interest from Aizen, who seeks to study him. Sensing rising tensions between worlds from his hidden sanctuary, Kisenemi emerges as a neutral figure, unaffiliated with either side, positioning him as a key observer to unravel Aizen's schemes.