when fighting yellow jacket, how do you beat him?
If you haven't beaten him yet, just attack his arms when they land and eventually he'll get stunned. That's when you hit him with a targetted fusion (Spider-Man and Wolverine for example). You probably have to hit him two or three times.
If you have someone with ranged attacks you can hit him in the stomach like deadpool with his guns.
When he rests his arms down and begins to regenerate you need to hit him with a Fusion. Can't beat him without using the Fusions.