Shank is one of the few prominent characters beside Gol D. Roger and Monkey D. Dragon whose abilities and powers are not fully revealed yet.
I think we can all agree that we haven’t seen enough of Shanks’ abilities. But, let’s see some examples of him demonstrating his powers.
When we first saw him with Luffy (in the first episode) and we see little of his fighting skills, mostly just his spirit, which he demonstrates against Higuma and then to the Sea King where, he shows his Haki.
Then after 10 years, with only one arm left, he is been visited by Mihawk on an island. We all know Mihawk is the best swordsman in the One Piece world. After we learn that they’ve had regular matches with one another, which means in terms of powers he has to be very strong to be a match for Mihawk.
Also then he demonstrates that he can take a blow from the strongest Yonko. And when he entered the Whitebeard’s ship his haki not only knocked out a lot of Whitebeard’s crew, but also damaged the ship. Also this caused Whitebeard’s scar to ache and have Marco and Jozu commend about his spirit.
Before the Summmit War Arc he was fighting another Yonko, Kaido, which is best known as the “Strongest Creature in the World”.
After that events, we saw him in Summit War Arc where he stopped Akainu with Armament Haki. And then he asked Blackbeard, which until then didn’t fear anyone, to fight and he said that it was not time yet for them to fight. Blackbeard understood on that moment he wasn’t ready to fight Shanks, which means a lot since Shanks stopped the war.
During the Wano Country Arc, he released a massive burst of Haoshoku Haki that paralyzed Admiral Ryokugyu, who was near the Flower Capital; whereas Shanks never left the Red Force, which was miles outside of Wano, stopping him in his tracks without needing to step foot into the country. Jinbe stated that such a display of Haki was monstrous.
Also It’s not just Shanks that’s strong, his crew members are strong too, Ben Beckman was able to make Kizaru stop for a moment during the Summit War Arc.
According to “One Piece: Vivre Card Databook” Benn Beckman is almost as strong as Shanks! His card says that Benn is incredible powerful in terms of physical combat. The card even says that “Comparable to Red Hair’s, this man’s existence is feared by even the powerful warriors of the New World!!”
Lucky Roo and Yasopp have each won their own fame as well.
Shanks’ crew in fact is the most well-balanced and impenetrable crew among the four Yonko crews.
Eustass Kid recently revealed that before he and his crew went to Big Mom’s territory, he lost his left arm in a fight against the Red Hair Pirates. It was not revealed which member of the Red Hair Pirates crew cut his arm.
So Shanks challenged everyone after the war: the three Admirals, the Fleet Admiral, overshadowed old school player Garp, Blackbeard (who had the strongest Logia and strongest Paramecia), but yet no one stepped forward!
*by Nilesh Jha