Amadeus Cho was a young scientist.
Cho worked with Bruce Banner in the experiment that eventually went wrong and turned him into the Hulk.
Cho would later develop a way for him to become a Hulk himself, but in a more controlled way, using tech developed by him, that would allow more control over the transformation.
During a monsters invasion led by Fin Fang Foom, Cho ended up defeated by the monsters when he tried to stop them. He joined the Avengers Academy and together with the other heroes they were able to repel Fin Fang Foom and his army.
At the Academy Cho tried to interact with his old friend Bruce Banner, Banner had been in his Hulk form for a while and did not remember him, despite not remembering him, Banner's Hulk persona became friends with Cho, and helped him train and get used to being a "Hulk".
Cho was also recruited to the Champions who were interested in recruiting him to the team before he even joined the Academy.
With his good friend Hercules, the Champions and a few more Academy students, Cho battled against the Chaos King to keep the evil god in its own dimension, since it was trying to break out of it, to turn their world into chaos and devour it. The heroes were able to stop the god, but just as temporary measure, since they believed he was getting stronger, and they wouldn't be able to stop him from breaking out in the future.