Ricochet: Once per turn, if Bouncing Boy KOs an opposing character or hits an opposing character with a critical hit, after the attack resolves, he can break away automatically, immediately move up to his full speed, and make one close combat attack against a different opposing character as a free action.

I noticed Bouncing Boy has a keyword called "Legion", but I don't think I've ever seen this keyword before. Is it a new keyword?
While there are indeed some keywords out there that are used by only a small number of characters, in this case "Legion" is an error. It is actually "Legion of Super Heroes".