Third season of Mushoku Tensei: Isekai Ittara Honki Dasu.

Shun Asanaga is a 15-year-old junior high school student with an optimistic and bright personality. One day, he finds a mysterious crystal in the office of his father, who is a scientist and businessman. When Shun touches it, the world becomes distorted, and he is sent into the world of Endra. Emilio, a prince of the kingdom of Endra, is nearing his 16th birthday and despises the reigning king, Delzain. Since Emilio is now at the age when he can inherit the throne, he takes up a weapon and attempts revenge. However, because Emilio is too weak, he is captured by Delzain and put in prison. When Emilio is in grief, the wall of his cell becomes distorted and Shun appears from there with two goals: return to his own world, and complete Emilio's revenge. What future lies ahead for the two boys trying to survive in Endra, yet raised in two different worlds? (Source: MAL News)

Ryouhei Arisu is a high school student with no ambitions and just wants to escape from what he feels is a meaningless reality. One night when he is with his two friends Daikichi Karube and Chouta Segawa, they see an abnormally large firework shoot into the sky, an event which signals a permanent change in their lives. Blinded by the incredibly bright explosion, the three find themselves transported to what is known as the Borderland. The only inhabitants of this world are participants of a deadly game where specific tasks must be accomplished if they wish to survive. As the three begin playing to determine how they can get back home, Ryouhei finds himself feeling alive for the very first time in his life.

What's a guy to do when his life suddenly changes while innocently enjoying a nice, cold drink after work? And I mean really changes. This middle-aged commoner now finds himself in the body of Liam Hamilton, the young son of a noble house teetering on the brink of collapse. Between his fervidly desperate father and his utterly apathetic brothers, the only bright side to his new situation is that Liam can finally try learning magic like he's always wanted. Little does he know his hobby of choice may be about to turn his life upside-down yet again! Will Liam be able to master the craft of magic? And will it be enough to save him from the shadow looming over his family...? (Source: J-Novel Club)