Foulberto does not possess any kind of powers other than very powerful dagger and throwing knife attacks. It should be noted that Foulberto tends to miss often, but usually one or two hits can kill a level 40 pirate, making fighting him incredibly frustrating, not to mention time consuming. Considering his level, his power, and his health points he is probably the second most dangerous enemy in the game. It is unwise (even if you are level 50) to attack him alone.