Go for the Napoleon complex.

Combat mode initialized. No matter what, don't let a single person get hurt!

Whatever it is these two robbers expected, it wasn't you. The speed at which you move catches them both completely off guard. As you run, you make note of their stance--position of their weapon, time in which it would take them to fire. What's strange, however, is as you near the position of the shorter man, his free hand reaches down for his belt where you don't see any other weaponry. Though there's a button, and he pushes it. You're inches away from grabbing him before his boots ignite with blue flames, and he goes soaring back down the length of the bus.

As he flies, he fires two shots, but both of them miss due to his awkward stance of being airborne.

However, the man with purple hair is nearby. Instead of going for you, he's moving towards the nearest passenger to grab them--a hostage! You glare at him as you reach out and thrust your palm towards his back. You stop. Hold on. Pull your punch. He's unarmoured. Then you follow through, still dealing a devastating blow to his body. The man grabs his sides, stops his gun, and collapses.

The shorter man has been let loose far too long now. His boots are off, and he's standing on the other side of the room with his gun aimed and ready. It fires, grazing your shoulder, and while it leaves a small mark, most of the blast deflects right off to burn a hole in the floor. You hardly even notice, and you certainly don't care. You stop in your tracks, and instead of pursuing him and risking somebody catching a stray blaster shot, you hold your left palm forwards. I know I can do this. I can feel it. Initializing laser cannon!

The man's eyes widen as the bottom half of that arm transforms. Segments painlessly open up, exposing shimmering metal beneath. They rearrange yourself, and after a brief moment, instead of said appendage ending in a hand, most of the thing is a glowing, humming laser gun of your own. With it aimed directly at him, you know you won't miss.

"Drop it. Now," you say.

His arms shake. With a nod, he lets the weapon fall to the ground, just like the other.