In fan fiction, Banner's rage and Hulk control can be shown in various ways. Sometimes, it's through mental discipline. For example, Banner might use his scientific knowledge to create a device that helps him regulate his emotions and thus control the Hulk. Other times, it could be a result of a deep emotional connection or a newfound purpose. Maybe he meets someone who makes him want to keep the Hulk in check for their safety.
One idea could be that Banner discovers a new element that has a calming effect on his Hulk - inducing rage. This element could be something he stumbles upon during one of his scientific experiments. He then figures out a way to use it to keep the Hulk under control, like making a serum or a device that emits the element's calming properties.
I'm not sure which anime resource you're referring to. The term 'canary in a cage' usually appeared in novels, comics, or movies, and it did not necessarily refer to specific anime works. If you can provide more information, I can try my best to help you find the relevant information.
Sure, She-Hulk is related to Hulk. Jennifer Walters, aka She-Hulk, got her powers because of a blood transfusion from her cousin Bruce Banner, who is Hulk. This connection is a key part of their storylines in the comics.
Captain America would be a great addition. His leadership and moral compass could guide Hulk and She - Hulk when they face difficult decisions. And his combat skills could come in handy during battles.
Rage comics can be copyrighted. If the creator of a specific rage comic has taken steps to register it for copyright protection, then it is copyrighted.