Little is known about what Shanks can do, as he has not been seen heavily engaged in battle yet; however, as a member of the Yonko in the New World, his raw physical power is immense, and is known to be one of the four strongest pirates in the world. Shanks did not fear Whitebeard, the world’s strongest pirate, and even had enough strength to clash with him, whereas some pirate captains quivered at the mere mention of Whitebeard’s name. Rockstar also used his captain’s name to convey to Whitebeard the importance of the letter he delivered to him. It was also stated by the Gorosei that he is one of the few people capable of stopping Teach. Admiral Akainu fought through many men and a fewShichibukai to get to Luffy, but when Shanks appeared, he did not challenge the Yonko.
He appears to be an excellent swimmer as well, having reached the young Luffy out in the middle of the sea before the Sea King could devour him. According to Buggy, as a young man, Shanks was a strong fighter and, had it not been for his ideals, he (Buggy) would have wanted him on his crew.
As a member of the Yonko, Shanks’ name alone commands great power, as Buggy himself proved; his assertion that he previously had a “brotherly bond” with Shanks was one of the many things that earned him respect from the Impel Down inmates. In addition, Buggy did not shy from using the names of Shanks and his previous captain, Gol D. Roger, to maintain his respect among them. Even the fact Buggy was seen back talking to Shanks was seen as a testament of Buggy’s own power to the former prisoners, not aware that the two had always acted like this and mistakenly thinking that it was because Buggy was not afraid of a Yonko. Shanks commands enough power to end the war at Marineford with just words; when he stated there was to be no more fighting, no one stepped up to challenge him, even though the Marines were fired up after the death of Ace and Whitebeard.
When Shanks offered to fight the very overconfident and pompous Blackbeard (who moments before had boasted about destroying the island and taking down Fleet Admiral Sengoku and Vice Admiral Garp after having already killed Whitebeard), Blackbeard declined and decided to leave, as it was too soon for he and his crew to take on Shanks.
Furthermore, when Shanks requested that Whitebeard’s and Portgas D. Ace’s dignity at death not be violated, Sengoku himself decided to call off the war and offered to take responsibility, showing that despite being a pirate, Shanks has earned Sengoku’s respect, something that no pirate other than Whitebeard is known to have achieved.
Shanks is usually portrayed as a swordsman. Shanks was capable of swimming ten years ago, meaning that he did not consume any Devil Fruit at the time when he was a rival to Mihawk.
While his use of his swordsmanship skills was only briefly shown, the fact that he was able to match a blow from Whitebeard with only one arm is a clear indication of the strength he puts behind his attacks. Shanks is also powerful enough to stop Akainu’s magma fist using his sword and Busoshoku Haki. Since Mihawk is classified as the world’s greatest swordsman, and Shanks is a former rival of his, it can be assumed that Shanks is an extremely proficient swordsman.
Shanks appears to have favored his left arm before he lost it, as he is always seen holding his sword in his left hand during flashbacks.
Shanks can utilize at least two of the three types of Haki. Shanks has shown mastery over the two types of Haki he has used. Even Whitebeard complimented Shanks for his Haki when he used it on his “visit”.
When Shanks and Whitebeard clashed with their weapons, the “heavens” above them split, hinting at the incredible Busoshoku Haki that the Yonko had imbued in them.
During the Battle of Marineford, he was able to imbue Busoshoku Haki into his sword to block a Logiaattack.
Shanks is capable of using Haoshoku Haki, an ability that only one in a million people can use.
After saving Luffy from a Sea King, Shanks was able to frighten it off with a single angry glare using this ability. Later, while Shanks was boarding Whitebeard’s ship for their meeting, a large amount of Whitebeard’s crew (experienced men who have survived in the New World) lapsed into unconsciousness and the ship itself began to take damage from Shanks’s mere presence. Whitebeard’s men attributed this to his superior Haki.
Oda mentioned in a SBS that Shanks could have knocked out all 100,000 pirates and fishmen opposing the Straw Hats during theFishman Island Arc with his Haoshoku Haki (Luffy managed to overwhelm 50,000).
So far, Shanks has only wielded a sword in combat. His sword is a large saber with a single edge blade and a large hand guard.
Shanks wielded two different swords during his time as an apprentice pirate aboard Gol D. Roger’s ship and during his stay in Luffy’s hometown.