On the last day of the Seven Day War, a boy was born in a small Rosharan village. This boy was not the firstborn of that family. There was a brother of about a year older. The two brothers loved and cared for each other. The younger idolized the older, while the older protected the younger.
One day, about 14 years later, the two siblings had gone far away from their farm, exploring, when a whitespine attacked. Immediately going for the weaker of the two, the younger brother was attacked. The older brother new that he should run, but he couldn't. Instead, he ran for the whitespine, and tackled it. This was destined to fail-he was a fifteen year old boy, and that was a storming whitespine. But as he jumped, he shouted something. "I will protect those who cannot protect themselves!" Suddenly, his body exploded in a flash of.... stormlight? Somehow, Tran killed the whitespine with that single tackle, his cuts and bruises melting away. Mahz gaped at him in awe.
Over the next year, the two brothers experimented quite a bit with his newfound powers. He was able to stick things together, change gravity, and attract things towards something. They also met a small wispy spren.
Then Darkness killed Tran.
This devastated Mahz. He began to slip into depression over the next months. But eventually, that depression turned to anger. He wanted to seek Darkness out and take his revenge. But he knew he wouldn't be successful. So eventually he made his decision. He chose to make the journey to the Nightwatcher and ask for the power to kill Darkness.
That's what he did. It took him over six months to get there, but eventually he did.
Mahz stepped into the valley, then stopped as the strange black spren began to creep up to him. This is it. This is my chance to make it right, he thought. To take my revenge on the dark man. He stepped up boldly to the spren and spoke his wish.
"I wish-I wish for enough power to take my revenge on the man who killed my brother." The Nightwatcher paused for a moment at this.
"I can't provide this to you myself." Mahz's heart sank, "But I can give you the potential to earn it yourself. First, I'll give you the ability to learn at an incredibly fast rate. Second, I'll ferry you to a world where you are far more likely to succeed. I wish you luck. Goodbye." And with that Mahz found himself in a strange land next to a shack.