Almost every action anime have strong old man that can rival the main character, this is the TOP10 Strongest Old Man In Anime:
Silver Fang – One Punch Man
Bang or “Silver Fang” is an S-class superhero from hero association, he lives in Z-City with the strongest man alive Saitama, Bang owns a dojo passed down from generations, he uses and teach the “Ryūsui Gansai-ken” fighting style.
Being the third ranked S-Class hero, he is very powerful. He is also a highly proficient martial arts teacher, He is even able to kill multiple dragon class enemies with ease. Bang known as an idol of martial arts, almost being like a god.
Zeno Zoldyck – Hunter x Hunter
Zeno Zoldyck is the previous patriarch of the Zoldyck family. Being a member of the Zoldycks family, He was trained from birth to kill using the art of assassination. He developed a great resistance against all types of poisons, and high tolerance of electricity.
Zeno is an extremely skilled Nen user, one of the finest to have been introduced so far. He using Transmuter and Emission skills, other than nen he also have high intelligence and know as master in hand to hand combat.
Hiruzen Sarutobi – Naruto
Hiruzen Sarutobi was the Third Hokage (Sandaime Hokage or Third Fire Shadow) of Konohagakure. He was a powerful ninja, known as God of Shinobi.
Hiruzen also renowned as The Professor due to his mastery of all forms of shinobi combat. Hiruzen’s knowledge extends to Fuinjutsu, Taijutsu, Bukijutsu, Ninjutsu, Kuchiyose no Jutsu, and Godai Seishitsu Henka. Hiruzen’s personal summon, Enma, could transform into an extendable staff that was as strong as diamond.
Master Roshi – Dragon Ball
Master Roshi (Muten Rōshi or Invincible Old Master), also known as the Turtle Hermit, he is over three hundred years old. Master Roshi was among one of the strongest humans on Earth, so powerful that when outputting his absolute maximum he was capable to destroying the moon using his strongest attack the Kame-Kame-Ha!
Makarov Dreyar – Fairy Tail
Makarov Dreyar is the 3rd, 6th and 8th Guild Master of the Fairy Tail Guild, as well one of the Ten Wizard Saints. As the guild master from Fairy Tail Guild, he able to use Fairy Law, one of the three legendary spells exclusive to Fairy Tail, Fairy Law is described as Makarov’s most powerful Magic.
Makarov is known for possessing a monstrous amount of Magic Power. By manifesting it in the form of light, something which is known as Giant Wrath, a battle with him was described as capable of causing extraordinary natural occurrences.
Jiro – Toriko
Jiro is a legendary Gourmet Hunter who is well known as the Knocking Master Jiro in the Gourmet Age. Before he gained the title of Knocking Master, he was known with more sinister title, the Rampaging Beast. Jiro was raised as a wild and brutal individual by one of the Eight Kings, the Wolf King Guinness.
Jiro one of the few people that have ability to change time, he was able to use Grand Knocking, An unarmed Knocking technique, it is strong enough to reduce the Earth’s rotational speed to near stopping point. When performed, natural disasters happen due to the planet’s rotation being slowed down. He is widely considered as one of the three most powerful people in the world, in the past, the “Gourmet God” himself feared Jiro’s power, he sealed off a part of his strength to teach him technique.
Issac Netero – Hunter x Hunter
Isaac Netero the 12th chairman of the Hunters Association and the chairman over the Hunter Examination Selection Committee. In his youth, he was considered the best Nen user in the world.
Netero is an extremely powerful practitioner of Nen user, He one of the few hunter who able to control over at least three Nen categories: Enhancement, Emission, and Manipulation. Being the grand master of the Shingen-ryū school of kung fu, he is a Master in Hand to Hand Combat.
Genryūsai Shigekuni Yamamoto – Bleach
Genryūsai Shigekuni Yamamoto was the captain of the 1st Division in the Gotei 13 and also the Captain-Commander of the whole Gotei 13. Yamamoto’s Zanpakutō is the oldest and most powerful fire-type Zanpakutō, and has greater offensive power than all other Zanpakutō in Soul Society.
Being the oldest and therefore the most experienced Shinigami, Yamamoto possesses an extremely massive and powerful Reiryoku. Its sheer strength is powerful enough to effortlessly add fear to his enemies.
Silvers Rayleigh – One Piece
Silvers Rayleigh also known as the “Dark King”, heis the former first mate of the Roger Pirates known as the “Right Hand of the Pirate King”. Rayleigh is able to use Haki the same way Shanks, Luffy and Whitebeard. He is able to use all types of Haki: Kenbunshoku Haki, Busoshoku Haki, and Haoshoku Haki.
Edward Newgate (Whitebeard) – One Piece
Edward Newgate, also known as “Whitebeard”, was the captain of the Whitebeard Pirates and was known as “The Strongest Man in the World” and “The Man closest to One Piece”, before his death in the Battle of Marineford He was a member of the Yonko that ruled over the New World.
Whitebeard ate the Gura Gura no Mi, a Paramecia-type Devil Fruit that made him a “Quake Man” and which was considered the strongest Devil Fruit within the Paramecia class. He one of the few people to have mastered all three kinds of Haki, He is able to use all types of Haki: Kenbunshoku Haki, Busoshoku Haki, and Haoshoku Haki.