Ultraman's Journey: Starting with Ryuki

[Kamen Rider fanfiction + parallel worlds + transmigration + Ultraman Tiga] Across the endless universe lie countless parallel worlds, each with its own unique story. Ultraman Tiga of the Ultra Multiverse stands at the crossroads where these worlds intersect. His figure appears in every corner, leaving behind incarnations across different dimensions. During an accidental transmigration, Tiga’s incarnation is swept away from his original world by ripples in spacetime and arrives in the Kamen Rider universe. Tiga, the giant from the ancient past, joins the Kamen Riders and fights alongside them...