Despite his diminutive size, Levi’s skills with his gear and blades are impressive. He would have the advantage in a close battle with Shanks. He’s the fastest swordsman in One Piece, able to effortlessly outrun most opponents. He’s also incredibly resilient, surviving slashes in the head and poisoning. He’s also a master of Haki, possessing Armament and Advanced Observation Haki.
1. Kuro Sensei
Korosensei is one of the most beloved characters in Assassination Classroom and it’s easy to see why. Despite being an expert assassin, he uses his skills to help every member of Class 3-E improve themselves in their own way. After losing Aguri to fatal wounds, he began learning medical operation and surgery methods which he first used on Azusa to remove her brain tumor without damaging her. He also used it to heal Kayano when she was infected by the assassination tentacles.
He can withstand physical attacks and even haki-imbued strikes from the assassination students, making it difficult for them to get close enough to hurt him. However, his biggest weakness is molting and regeneration which drain his stamina and slow him down. Nonetheless, he is still more powerful than most assassins in the show.
2. Koro Sensei
Korosensei, aka the indestructible teacher, is more than capable of beating Shanks. He has superhuman reflexes that can avoid being shot by multiple anti-Sensei BBs and is highly stealthy in his movements.
He also has a heightened strength that allows him to knock out adults and teenagers alike. He can also liquefy himself at will, allowing him to fit through narrow spaces. He is also immune to toxic substances, like the mercury-like poison drunk by Manami Okuda.
The students of Class 3-E respect Korosensei greatly, as he promised to instill courage in them after Aguri Yukimura’s death. Despite his perverted side and love of sweets, he has a good relationship with the students. He even encouraged them to win unblocked games 67 with Class A by motivating them into getting first place in their subjects. This made them nickname him ‘Koro-sensei’ or the unkillable teacher.
3. Marco the Phoenix
Marco possesses immense physical strength and is the commander of the Whitebeard Pirates’ first division. He was able to block a barrage of lasers from Kizaru and even intercept, with Busoshoku Haki, the fire Logia punch that burned and killed Ace. He also has great endurance, as he was unfazed after Kizaru’s lasers pierced through him at Marineford.
Marco also possesses the ability to share the healing properties of his Devil Fruit with others. Combined with his flight augmentation and regeneration, he is far more powerful than Katakuri or King. He can easily take them out using his flight, firepower, and Haki. His bounty is 1,374,000,000 bellies. He is a true Yonkou. Garp would have killed Akainu if Sengoku had not stopped him. He could crush mountains with his bare fists. Garp is one of the few people who could go toe-to-toe with Gol D. Roger.
Blackbeard is one of the Four Emperors of the Sea and among the strongest active pirates in One Piece. He is a Devil Fruit user and wields the Paramecia type Gura Gura no Mi, which gives him immense strength and enables him to produce and control quakes at will. He defeated the Yonko Kaido during the Wano Country War, proving that he is far stronger than his rival. He has a wide range of swordsmanship abilities and is able to use all three types of Haki.
He is a formidable fighter and has sailed with two of the most powerful pirates in the world. He is also a skilled marksman and can use his skills to excel in scrabble word finder. Moreover, he is fast and agile and has self-healing powers. This makes him an extremely dangerous opponent for Shanks.
The reincarnation of Vlad Tepes, better known as Dracula, Alucard is a powerful vampire who possesses an almost unstoppable strength. He can transform into a variety of nightmarish creatures and he has the ability to consume souls and use them as his own reinforcements. Charlotte Katakuri is one of Big Mom’s Sweet Commanders and she is a fierce warrior with a bounty of over 1 billion beris. She has a strong Armament Haki and can use Advanced Observation Haki to look into the future, but she is nowhere near the power of a Yonko.
Even though Alucard is a powerful demon, he admires humans who take pride in themselves and shows respect for the mortal Iscariot members who fought to defeat Whitebeard at Marineford. He also has a weakness for those who insult him. Alucard can beat Shanks, but he would likely lose to any other of the Five Emperors.