Read manhwa The Berserker’s Second Playthrough / Second Life of the Berserker / The Berserker’s Second Playthrough in the Game / 게임 속 2회차 광전사
The protagonist, having possessed a berserker character within the game, has finally slain the Great Demon and cleared the ending after many events.
He believed that was the end.
However, before his eyes was not an exit to the real world but a [New Game+] button to start another run.