Dead Bone is the Legendary Life known as the King of Skeleton, inherently wielding the Great Force of death.
When he evolved into a Legend Two Stars, he prematurely possessed the 'World Seal·Death', and made a conspicuously rapid advance in the concept of death.
Yet, Dead Bone always believed that possessing only 'death' was insufficient.
Death and rebirth are two sides of the same coin.
Undead are the deceased, but the birth of an Undead is also a form of rebirth.
Only the transition from death to life, the cycle of life and death, is the true path of the Undead!
Dead Bone even developed a legendary side Great Force 'Life and Death Cycle'—when an Undead dies in battle, they gain the 'Force of Life', and when an Undead is resurrected, they gain the 'Breath of Death', especially, allowing for an endless cycle of life and death.
This is akin to stepping on one's own foot to reach the heavens, a Great Force that defies natural laws!