He was ready... that's what he told himself before he tried to do what his cousin did. He always looked up to Rainbow Dash, so naturally he wanted to try the sonic rainboom. But as Hyperion sat there in a crater created by his failed attempt, he thought that maybe he needed to take a break from training for the Shadow Bolts and do something else. So, he did something he had not done in over ten years. He left his home in the Everfree Forest and he couldn't help but smile at the sun he had long missed, "How about I go help somepony for a change," Hyperion said to himself "maybe that'll take my mind off training for a while... Now, is there anypony out there that needs help?" And with that he took to the skies.
EDIT: ...
"Well, I certainly missed a lot in a decade," he said as he overlooked the smoldering remains of what used to be his house. But after what his parents did to him, by letting him be banished to the Everfree... he felt neither sadness nor a need for revenge. "But who... or what what could this?"
@MagicalStarRain
With nothing left to do, Hyperion left... and he never looked back. He simply chose a direction and started flying. Once he got to his cruising speed of Mach 5, he kept that velocity for a few hours until at one point, he thought that maybe he'd give the sonic rainboom another try. But before he started to accelerate, he saw something. It was a little unicorn walking away from some smoldering rubble which he assumed was her house. He landed in front of the Unicorn.
"So... what happened to you?" He asked the unicorn.