Usopp/Abilities and Powers

According to Oda in a discussion with Mayumi Tanaka, Luffy's voice actress, 'no matter who joins, he always wants Usopp to be the weakest' since otherwise it might upset the balance of the story. Oda also states that this is because Usopp is the closest in strength to a regular human compared to the others and thus this portrayal can be easily related to by the average person's own strengths. Since early in the series he has struggled to match the physical feats of the stronger characters, and needs his weapons or ammunition to take out foes. He used to be a huge coward and often wanted to run away immediately, a trait he still carries to a lesser extent after his two years of training. This, coupled with his easily getting distracted or confused in battle have often made him less effective than his real potential as a sniper. So far, he appears to have moved past this after his training and takes better advantage of his wit and strategy.

Both his physical and mental strength have all increased greatly during the two years away from the crew, as he was able to quickly dispatch all of Caesar's men on his own. While many of his attributes lie mainly in his ability to hit nearly anything he sets his sights on with his slingshot,  he is now shown to be strong enough to keep both Robin, Luffy, and himself afloat in freezing water.

Sniper Skills and Creative Wit
Usopp's role in the crew is that of the sniper, and also a jack-of-all-trades craftsman. Since early in the series, he was shown to have inherited much of his father Yasopp's exceptional marksman skills. In a challenge to shoot a whale-shaped weather vane that was far off in the distance, he managed to shoot the center of a jewel on the whale's crown, which amazed a bounty hunter named Daddy Masterson, an ex-Marine sniper.

His abilities rely primarily on his resourcefulness and understanding towards engineering (such as easily understanding the tunnel networks made by Miss Merry Christmas), and using the cannons of the ship with great ease. He is also very analytical in battle. For example, in his battle against Caesar Clown he understood that even though Caesar Clown had the Gasu Gasu no Mi, therefore making him a Logia type, he would still explode if he was exposed to fire as he was still just gas. He then later understood that a plan would not work as Caesar Clown was in control of the gases around him and that if he removed the oxygen from the atmosphere, the flame would no longer burn.

He has also been proven clever enough to stop a foe like Caesar Clown from escaping by surprising him with a pair of Kairoseki handcuffs that he fired at him, effectively negating his Logia powers.

His marksmanship is nearly unmatched, hitting Spandam and some Marines from a distance of over a mile (out-distancing even the guns the Marines had) with the wind against him. In order to stop Sugar a second time, he demonstrated his ability to calculate and predict trajectory angles, influence of wind and distance, and even incorporating booster shots to into his projectile; thereby allowing him to hit his target located indoors, physically located too far away to even be visualized, through a small opening in a window.

Usopp also has impeccable eyesight, and has on more than one occasion seen or noticed things before his crewmates. Examples of this include being the first one to see Gekko Moriah inside the stomach of the gargantuan zombie, Oars, and being the only one able to see the harpy Monet watching them on Punk Hazard.

Prior to the introduction of Franky, Usopp served as the Straw Hat's sole unofficial gadgets and mechanics specialist. His creative engineering has resulted in the creation of both the Clima-Tact and Kabuto. He also appears to have some knowledge concerning chemistry, being solely responsible for manufacturing the highly innovative slingshot pellets, or "stars", that he uses for ammunition. For other more complex activities, such as acting as the shipwright for the Going Merry, he is largely inexperienced, as he was barely able to keep the Going Merry going doing patchwork repairs. As Franky pointed out, his skills are amateur and he barely knows how to use a hammer correctly for such jobs. After Franky joined the crew, Usopp gladly let him take over maintaining the ship, even agreeing to Franky's request to assist him. In return, Franky provided a workshop for Usopp to work on his gadgets and creations, something he is more at home with. Even Franky admitted that his skills in gadgets are considerable.

Physical Abilities
Usopp's endurance and will power is considerable as well. After a major battle, Usopp tends to have severe injuries often caused by his determination to reach his goal. He will attempt to continue even with his injuries. A prominent example of his incredible durability can be observed when Usopp was hit in the face by Mr. 4's 4-ton bat, and smashed repeatedly through walls by Miss Merry Christmas, and not only survived, but was able to continue fighting. This has been seen more recently with their fight against the legendary Golden Lion Shiki where he was the only Straw Hat that managed to remain conscious after the battle.

Usopp's endurance after the timeskip was once again displayed when he was attacked by a drug enhanced giant child from Punk Hazard and almost immediately got back up ready to attack. He was then suffocated by Caesar Clown with his Gasu Gasu no Mi abilities before taking a direct "Gastanet" attack only to come out of it with a few bruises. This emphasizes the fact that his training and new found body are not just for show.

Another one of Usopp's attributes is that he is a fast runner. In battle, Usopp uses hit-and-run tactics, and works best as part of a team where there are more physical fighters to watch his back. This is due to the fact that he is so high-strung and jumpy, and he often gives into his basic survival instincts: fight or flight (usually choosing flight), although this seems to have changed after the timeskip where he is shown to be more confident in his abilities. Even before his extensive physical training during the timeskip, Usopp was capable of running faster than a Pacifista while carrying a wounded Zoro.

Haki
Usopp has awakened his Kenbunshoku Haki, as he was able to see auras of Luffy, Law, and Sugar, who were in the royal palace, from a plateau near the Corrida Colosseum. With this, he was able to pinpoint his target and snipe her down from such a distance. Usopp does not yet have control over it as he just awakened it during his attack to knock out Sugar.

Miscellaneous Skills
Usopp is also a great artist, as he proved in the beginning of the series when he made his and the Straw Hat's Jolly Rogers in response to Luffy's poor art skills. A running gag involves Luffy and Chopper building simple snowmen or sand castles only for Usopp to show off his vastly superior skills with a professional work of his own. He's also boasted, much like Luffy and Sanji, that he has never been ill during his life (which impressed Vivi). Usopp used to make spiders fight when he was young and knows how to handle them without being bitten by their fangs or being poisoned in the process.

Likely due to his time with Heracles, Usopp has gardening skills, which he uses to cultivate Pop Greens for his arsenal after the timeskip.

Weapons
Usopp has outstanding marksmanship abilities with his weapon of choice, the slingshot, which is the primary reason why he serves as the Straw Hat's Sniper, and also why he is often tasked with anything that needs precision at a distance, most notably the Thousand Sunny's "Gaon Cannon".

Usopp has developed other attacks unrelated to projectiles, though they are mainly jokes. These include the 5 Ton Hammer and others. After the Skypiea Arc, he has started using Dials for attacks such as using the Breath Dial to house explosive gas, using the Flash Dial to blind his foes, and using the Impact Dial to absorb and return blows.

Usopp improves his sight and/or focus with special goggles. He purchased an upgraded pair in Loguetown, but the actual scene of him purchasing them was cut out in the 4Kids dub. The scene was also absent in the original manga due to a lack of room. Since the timeskip, he has discarded those goggles, and gained a new pair which he typically wears around his neck.

Ginga Pachinko
His slingshot also known as the "Ginga Pachinko", was his primary form of combat, and he had many different types of ammunition in which he carried inside a large shoulder bag of his. He also often uses eggs in order to blind his opponents and rocks whenever he runs out of ammunition (before the timeskip).

Kabuto
In the Enies Lobby Arc, Usopp introduced a new weapon, the "Kabuto", a slingshot with five bands connected to a long staff. It has much greater power than his normal slingshot because it is powered by Skypiean Dials. Its range is enormous, and Usopp can use it to strike individual targets quite accurately from seemingly impossible distances.

The exact workings of the Kabuto are unknown, except that the five bands increase stability (and thus range), and the Dials in the instrument add spin to the ammunition similar to rifling to increase damage and accuracy, as well as allowing Usopp to choose a variety of different Dial effects to add to each shot. Usopp explained some of the workings of Kabuto to Perona during their fight, but was interrupted before he could finish.

Kuro Kabuto
After the timeskip, he uses a new slingshot called "Kuro Kabuto", which retains the five band design of the original "Kabuto". The only immediately clear difference is that it is colored black and has a smaller size (whereas the first Kabuto was a staff, the new one is nearly the same size as his original slingshot).

Grow Up Kuro Kabuto
His new Kabuto also has the ability to take on a more powerful and larger form that he calls "Kuro Kabuto Chomping Grass". After being given water, it eats up anything in the immediate area, such as rocks and boulders, to use as ammunition. This technique allowed Usopp to capture Caesar, along with Buffalo and Baby 5. He can expand it to an even larger size which he dubs "Super Grow Up Kuro Kabuto" which is useful for particularly long range attacks.

Pop Greens
After the timeskip, Usopp is shown to be quite adept in using Pop Greens, as shown when he defeated some of the Impostor Straw Hat Pirates by creating a carnivorous plant that resembled a monstrous venus flytrap with tendrils. During the Fishman Island Arc, he also manages to save the crew and the Thousand Sunny from being crushed by boulders by using Pop Greens to grow sea weed like plants to trap the boulders, and again, when they encountered the New Fishman Pirates in the Ryugu Palace, he used a giant flower with a terrible smell to deter them.

In another battle with some of the New Fishman Pirate lackeys, Usopp is also seen using a particular type of Pop Green that makes bamboo shoots erupt from the ground, impaling or gouging his enemies. Later in a fight with Daruma he shoots a special exploding Pop Green into the tunnels made by Daruma's teeth, which explodes in the shape of a skull. He later uses one that transforms into a giant wolf, with the bulb that it grew from acting as its nose, which releases a stunning shockwave that is 3 meters in diameter, to finally defeat Daruma.

During his trip to Green Bit with Robin, Law and Caesar, Usopp's Pop Greens have been shown to be powerful enough to take out a full grown adult Fighting Fish.

Usopp has also been shown to be able to catch opponents off guard by using the Pop Greens in intricate ways. Also while Pop Greens are useful for battle purposes, some can also be used for utility functions (likes boats and paddles).

He keeps a small garden on the Thousand Sunny for growing more Pop Greens, in order to maintain a continuous supply of seeds.