LIFE OF THE GOD'S EXPERIMENT

Everyone knows stories of being transported to another world via a truck, magic, reincarnation or even being called upon by a mythical being like a god or goddess. Being given a second chance at life or even selected for a quest to defeat an evil being like a demon king and become a hero.  But what if there's someone who got Isekai'd by a god purely for sadistic entertainment? What if he didn't get dragged into one world but multiple? Hundreds or even thousands of worlds? Making him experience life over and over again in different ways and different lifetimes. Some joyful and many full of misery, purely for the god's entertainment. And to make it worse as the cherry on top, there was absolutely no reason for his selection. The god purely chose him at random for his own sadistic entertainment. Thus begins the story of this unfortunate young man, who was dragged into this fucked up scenario without consent and yet he has to keep on living simply because he has no choice in the matter.