Usopp is the most arrogant of the crew and has a cowardly attitude, but gets very excited when things turn to battle. His abilities as a liar are unrivaled anywhere in the world, making most people believe anything he says. Despite his low reputation and insensitivity towards insults and intimidation, Usopp does not seem to be above changing his own views if proven wrong: after Usopp’s humbling defeat at the hands of Kuro , he starts to question his prideful ways and decides to become more courageous . He also willingly apologizes for trying to assassinate Luffy during their first encounter (for such an action is punishable by death in Baratie).
Usopp was originally obsessed with becoming a great pirate like his hero “Red Haired” Shanks, but after the two years of training to improve his skills, Usopp’s original dream was broken. Luffy helped him realize that he cannot become someone he is not. With the encouragement of his new-found friends who did not care about his external appearance or lack of strength, Usopp became more compassionate and braver, while retaining a childlike attitude.
Usopp uses pop green (referred to as “homei-gami” in the manga) for most of his attacks; which are basically pellet capsules that explode with varying degrees of power . He has also used slingshots and cannons in battle to shoot projectiles at people and objects.