Item from Bleach by Tite Kubo
Not truly an item but a being reduced to a limbless, eyeless corpse sealed in crystal — the linchpin holding all three dimensions (Soul Society, Hueco Mundo, World of the Living) in balance.
The Soul King is Bleach's darkest secret and its most tragic figure. Originally a powerful being, he was mutilated and sealed by the original Shinigami to serve as a dimensional anchor — his existence prevents the three worlds from collapsing into each other. The Royal Guard protects him not out of reverence but out of necessity: if the Soul King dies, reality ends. Yhwach — his son — killed him during the Thousand-Year Blood War, and Ichigo was briefly forced to stab the corpse to stabilize it. The Soul King's severed body parts became independent entities: the right arm became Mimihagi (worshipped in Rukongai), the left arm became Pernida (a Sternritter). Kubo never fully explained the Soul King's origins, leaving him as the series' greatest unanswered question — was he a god, a sacrifice, or a prisoner?
A humanoid figure with no arms or legs, sealed inside an enormous crystal in the Soul King Palace. Eyes absent. Faintly glowing. Tubes or veins of energy extend from the crystal into the palace structure. Motionless. The body appears preserved but not alive in any conventional sense — more like a spiritual battery than a living being.
Also known as: Soul King, Reio, Reiō, The Lynchpin