Shiki Granbell (シキ・グランベル, Shiki Guranberu) is the sole human denizen of the robot-inhabited theme park planet Granbell,[ch. 1] from which Rebecca derives his surname.[ch. 3] Found beyond the Sakura Cosmos as an infant by Ziggy,[ch. 14] Shiki learns the Ether Gear "Satan Gravity" (サタングラビティ, Satan Gurabiti) to use Ziggy's gravity abilities,[ch. 82] which include altering the weight and direction of gravity for himself and others,[ch. 1] creating gravitational fields and energy spheres,[ch. 8, 25] and converting kinetic energy into gravity.[ch. 66] He also suffers from a paralyzing fear of bugs and anything resembling them, such as lobsters.[ch. 15, 108] After being chased away from Granbell by the dying robots due to his over-attachment to them, Shiki aspires to make as many friends beyond his planet as possible,[ch. 1] which he expresses through unprompted offers of friendship towards new people he meets.[ch. 1-3] He subsequently earns Edens Zero from Elsie Crimson and inherits Ziggy's title of "Demon King" as the ship's leader,[ch. 15] using the ship to search for Mother in the hope of accomplishing Ziggy's failed dream of finding her.[ch. 3, 13] However, after Granbell is destroyed by the reactivated Ziggy, Shiki promises to defeat him and wish for Mother to restore the planet.[ch. 101-104]
Continuing his theme of naming protagonists after seasons, Mashima chose the Japanese word meaning "four seasons" (四季, shiki) for the main character of Edens Zero to represent the culmination of his previous works. Mashima originally used Ziggy's name for Shiki in the manga's earliest draft, taking inspiration from the song "Ziggy Stardust" by singer David Bowie, which the author listened to frequently during the manga's production.[vol. 9] In the booklet packaged with the first tankōbon volume's special edition, Mashima wrote that he often forgets to draw details of the character such as the patch on his cheek, and that he alternated between design attributes during development, such as giving him white hair instead of the final black, and whether or not Shiki would wear goggles. Other concept drawings depict Shiki wearing a bracelet that transforms into a gauntlet as an early concept for his Ether Gear.[5]