The Master of Games is an antagonist from Teen Titans Go!. He appeared in the crossover movie, Teen Titans Go! vs. Teen Titans.
In "Teen Titans Go! vs. Teen Titans", The Master of Games opened a portal to another dimension and went into the Teen Titans Go! Universe. There, he kidnapped the Teen Titans and brought them into his battle arena. The Master of Games introduced himself to them and told them what he was all about. He said that they were part of a multiverse and that there were many other versions of themselves in different universes. He was able to travel do different dimensions with a magical orb known as the "Worlogog".
The Master of Games showed the Teen Titans their adversaries and they would be the Teen Titans from the dimension, wherein the original Teen Titans series took place. The Master of Games pitted the two teams against each other in an event called "The Tournament of Titans". The Master of Games then sent them to a huge battle arena, where tons of fans from all across the galaxy cheered them on. The rules were simple. Both teams had to fight each other and whoever won, would reign victorious, while the losers would have their Earth destroyed. Raven suspected something was up but the other Titans were too giddy to fight themselves to question anything.
In the final moments of the fight, the last ones standing were the Raven and the original versions of Robin, Cyborg, and herself. Raven was too afraid to use her powers because it was said earlier by Trigon that if she overuses her powers, she will set a demon free from her head, which will take total control of her and help him take over the world. Raven decided to forfeit the fight and let the enemies win, but The Master of Games refused to let her leave until there was an official winner.
Raven was forced to keep using her powers, coming closer and closer to unleashing her demon. The original Raven realized what was going on. The Master of Games was intending on making TTG Raven abuse her powers, so she could unleash her demon. There was a giant diamond that was getting fuller the more TTG Raven used her powers. OG Raven tried to save TTG Raven to stop this. The giant diamond was three-fourths of the way full before OG Raven used her white magic to stop TTG Raven's demon.
The rest of the OG Teen Titans broke out of their prisons and attacked the Master of Games, telling him to fess up and tell them what was really going on. The Master of Games revealed the truth to them by transforming into Trigon, revealing that he was actually Trigon in disguise the whole time.
He is one of the three new villains to be introduced in "Teen Titans Go! vs. Teen Titans", with the other two being Megan Claus and Gentleman Ghost.