Gods' Games We Play, Vol. 4 (light novel) — Kei Sazane

Within the maze called Lucemia, players continually respawn at the starting point upon death, with no option to leave the game. When it is announced that players around the world are trapped in one of the Gods' games, Fay's team and other skilled apostles form a rescue squad. Things start to look up when they discover a save point but that doesn't solve all their problems. They still have to defeat the last boss to finish the game. However, apparently this labyrinth's last boss—the god who created this game—died of boredom! They worry that escape may be impossible...but then they get a visit from the “Undefeated” God, Oroboros, in human form!