The person Kon was talking to didn't bother with the stairs, instead jumping on the railings of the stairs and flipping off the railing to land next to him. The reason he was able to do the flippy thing so effortlessly was because he was a ninja, just like Raph. And he was a turtle, just like Raph (albeit a much tinier one).

And that was because, like Raph, he was also Raph.

"What?" he asked, voice irritable. He'd been playing a video game.

Kon was an okay guy but man, he was annoying sometimes - and hello, what.

What.

At the sight of the other Raph, Raph's eyes nearly bugged out of his head.