He has tried to change the future before.
When he first learned he could see the future, the Master of Masters didn’t know the consequences and his mother as well as his name were lost because of it.
He saw his mother, the only one to raise him, die in an accident during one of his future vision bouts. He had seen her future before, but it was usually minor.
He wanted to change this.
So he did. He asked her to stay home that day to prevent her from dying of anaphylactic shock when she was given the wrong lunch at the blacksmith’s she worked at. He made her lunch instead.
The next morning, all of her possessions and her body were gone. Panicked, he had ran to their neighbors. Then he went to her coworkers. Then the police. No one had ever heard of her.
However, he wasn’t satisfied with just that. So he tried again, this time with a friend he had just made.
The same thing happened - they disappeared from this world.
He did this over and over and over again, each time learning that no matter what he did, no matter how little a change he made, someone disappeared.
From then on, he realized that it was his fault. He had gone against what he had seen and paid the price. If anyone was to go against their fate, the world would make the anomaly vanish so the timeline could continue as it had before without interference.
And so, to prevent anyone from ever finding out about what he did to learn of this consequence, he let himself disappear from the timeline. Not fully, no. Some people still remember a shade of who he was.
But eventually, those people passed on.
And the anomaly known only as the Master of Masters was finally gone.