Disappointed by Shocker's numerous failures to defeat Kamen Riders Ichigo and Nigo, the Great Leader of Shocker, secretly met with an executive General Black from Geldam, an organization from America to discuss the merging of their two organizations. They eventually put their plans into action after the death of Ambassador Hell.
As part of their agreement and seeing that the other leaders of Shocker were unfit to join the new group from Great Leader of Gel-Shocker's pov, Black sent the Geldam kaijin Ganikomol to exterminate the remainder of the Shocker Combatmen so they could be replaced with stronger Gel-Shocker Combatmen. The Great Leader had all former Shockers personnel purged, blowing up various remaining Shocker secret bases worldwide and having all of the Shocker Combatmen liquidated and replaced with Gel-Shocker Combatmen. Ganikomol was later encountered and defeated by Kamen Rider 1. Although Rider 1 destroyed Ganikomol he was unable to prevent the merger of Shocker and Geldam.
Rising from ashes of Shocker came Gel-Shocker. Despite being led by the Great Leader of Shocker, the majority of the organization's resources were provided by Geldam. And when Gel-Shocker was ultimately destroyed, Geldam went down with it.
Gel-Shocker Combatmen are the main foot-soldiers of Gel-Shocker. They wear bright purple and yellow costumes, covering their entire bodies from head to toe. Aside from the Shocker Combatmen's standard disguise abilities, they were also capable of traveling from one place to another by transforming into sheets that would drop down onto unsuspecting victims and turning themselves invisible. They were also physically superior and authoritative to their predecessors, able to take more blunt violent abuse without lowering combat performance.