As a Catachan native, the jungle is his element, and he is capable of taking on entire enemy forces through his innate skill at jungle and guerrilla warfare. He strikes from seemingly nowhere and disappears back into the dense jungle. He is famous for his excellent sniping skills.
Marbo's characteristic weapon is the ripper pistol, a weapon firing toxic, armour-piercing rounds. For a melee weapon he carries the Envenomed Blade, a unique Catachan knife, the blade of which is coated in deadly venom.
Sly Marbo is originally based on the protagonist of the movie First Blood, John Rambo, Marbo is in fact the anagram of Rambo and Sly is the nickname of Sylvester Stallone, the actor who plays Rambo.