Doctor Impossible has at least two, his prison break and defeating the entire Champions (minus two) one by one after they catch him at a coffee bar.
In the prison break he takes down two far younger superheroes (one of which is clearly prepared to kill him) and every guard he encounters. The high point is when he strolls down a corridor cheerfully whistling, dragging one of the unconscious heroes behind him, while striking down guards with the chain that previously shackled him. Doctor Impossible is right, sometimes it's best just to work with your hands.
The Champions fight at the coffee bar is even more impressive, as Doctor Impossible has about a minute to prepare after being surprised in a Starbucks, with only a single gadget and facing two-thirds of the superhero team. He takes out Feral in one punch (by predicting when he would attack based on physical tics Feral had shown in earlier battles), knocks Blackwolf out in no time after distracting him with a cheap lie, and then gets Damsel to drop him by surprise-kissing her in mid-flight to administer a knock-out gas.
Special mention has to go to his takedown of Fatale in three seconds. By remote control.
He also beats up CoreFire with the little bit of power left in the Pharoah's hammer. "Nelson Gerard says hello." Funnily enough this also saves the world.
Mr. Mystic's near-takedown of Doctor Impossible. It was pretty clear that he could have stopped Doctor Impossible if he wanted. He had some sort of plan going on
Or if you believe in the other interpretation, Mr. Mystic has made himself one of the most respected and mysterious superheroes in the world using nothing more than particularly good stage magic, which is still pretty awesome.