Who won the duel between Tenth Generation and Muto Game in the Game King gx finale?

Muto Game won.

At the end of the story, Tenth Generation and John teamed up to defeat Fujiwara, but DARKNESS's original body appeared, and John was unable to fight because of his battle with Fujiwara Yusuke, leaving Tenth Generation as the last hope. He awakens the lost and shut-in people with hope and faith, and defeats Darkness.

After the graduation ceremony, while everyone is still partying at the graduation ball,

Yuujo Tokoyo has already packed his bags, and is ready to leave in silence, but he is guided by the feathered chestnut ball to a real graduation duel with the legendary King of Gaming, Muto Gaming. At the end of the game summoned the legendary three gods card of the sky dragon, then Atum appeared, Atum launched a trap black magic resurrection coffin, black magic girl and earth flying squirrels as a sacrifice,

launching the elf realm in the racial conversion, according to the black magic resurrection coffins, according to the effect of the Osiris, from the graveyard special summoned Osiris, according to the effect of the Osiris, the Osiris ATK increased by 5,000, the glittering flame winged man effect invalidated, the glittering flame winged man effect invalidated, the glittering flame winged man effect nullified. Human effect is nullified, Glitter Flame Wingman ATK-2000, Flame Dung Beetle is destroyed, Neos ATK-2000, and Tenth Generation doesn't have a card that can match Osiris, and it ends with Tenth Generation losing the duel.

Expanded:

Game of Thrones GX Plot Summary -

In order to capture the Three Illusory Demons, the Illusory Demon Emperors, who have the power to destroy the world, and who have been sealed in the underground ruins of the Dueling Academy Rabiel, Thunderfall Emperor Harmon, and Divine Inferno Emperor Uriah, a mysterious group called SEVEN STARS emerges. Accordingly, the dueling academy side of Youjou Tokoyo, Tenjouin Akane, Manjoume Jun, Misawa Daichi, Maruto Ryo, Kuronos de Medici-sensei, and Daitokuji-sensei,

are chosen to be the guardians of the Seven Stars Gate Keys, and fight against the Seven Stars hunters. It is discovered that Daitokuji is also one of the Seven Stars, and that Daitokuji-sensei's true purpose is to train Tokoyo to have the power to defeat "The One"...

Shortly after defeating the Seven Stars, the mastermind behind it all, Chairman Kagemaru, suddenly appeared and unleashed the true power of the Seven Star Gate Key, opening the ceremony to awaken the power of the Three Illusionary Demons.