My Gift Lvl 9999 Unlimited Gacha: Backstabbed in a Backwater Dungeon, I'm Out for Revenge!

Premise

God created nine races in the ancient times. Humans were the weakest, most ridiculed race among them. Light, a human boy, was fortunate enough to be invited to join a party of all nine races called the "Assembly of the Races." He was happy being a member for a while, but that was a short dream. His hopes were only to be betrayed by his fellow members at the largest, most heinous dungeon "Abyss." After surviving by himself at the bottom of Abyss, Light learns the true meaning of his gift "Unlimited Gacha." Light will rise from the worst despair to build his own empire of the strongest players.