This is El Mariachi, Robby's "Super" form.

He's pretty much Robby's alter ego and pretty the opposite of him, unlike Robby who's shy and very go-happy El Mariachi is badass and straight-forward, if he wants something he does it, and if you piss him off a witness protection program wont help you.

The guitar pick is what gives him his powers, it's made out of a weird material and posses powers of unknown origins, it is an item a lot of people search for weather it's for money or power, but the pick is safely guarded by the Rodriguez-Dryphus clan.

The powers that are given to Robby dont really fit to a pick.
Between the powers:
Top notch accuracy(he can pretty much throw and shoot anything and hit the target).
Kung fu?
He can shoot lasers through the headstock of his guitar(this thing was created BEFORE I knew who Santona of the dead was).


Fun fact:
Robby is not the first El Mariachi, but he's the first to use an electric instead of Spanish guitar.

As said, Robby is not the first El Mariachi.
The guitar pick is handed down from grandfather to grandson at a certain age and then the grandson must continue the tradition.

El Marciachi's activity was through out all of Mexico but a lot of his activity was centered in Miracle city.
The previous El Mariachi(Robby's grandfather) was the arch enemy of El Puma Loco, AKA Manny's grandfather, that is the reason Manny and Robby had a rough start.
The reason that El Mariachi wasnt seen for such long time was because Robby's grandfather took an early retirement of unknown reason.

El Mariachi was always a lone wolf and always acted by himself, he hated when someone tried to assist him and it is seen through out the predecessors.

Now that he's returned, who knows what will happen.