Originally Posted by
Captain Morgan
Off the top of my end, he's speed stolen a high end Amazo unit that was pretty much taking apart the Justice League, dialing him down from Flash fast to normal human speeds. Jay Garrick has stolen Black Adam's speed, and he's the diet coke Flash. Wally has noted he could do it to Superman but opted not to because it would do devastating damage to their environment. Not sure if current Flash can speed steak, though current Wally certainly should be able to since he's literally just post crisis Wally powered up.
Oh, he's also balanced the kinetic energy of moving the entire earth to keep it from being destroyed in the process. I'd need to double-check if there were asterisks on that.