Ymir Fritz (Attack on Titan) was the first and most powerful Titan...
...having the power of all the Nine Titans combined. The Curse of Ymir is even believed to exist to prevent any other Titan from surpassing her power.
Due to his immense power, longevity, and aging abilities, Baraggan Luisenbairn (Bleach) ruled as the undisputed ruler of all Hollows for countless eons.
As Primera Espada, Coyote Starrk (Bleach) was one of the very few Hollows who's power...
...rivaled or surpassed even Baraggan's.
Out of all the Arrancar, Ulquiorra Cifer (Bleach) was the only one to have achieved a second stage to his Resurrección.
Ikomikidomoe (Bleach) was an extraordinary Hollow of such power and with nigh-limitless potential that even Baraggan Luisenbairn had respect for it.
Genryūsai Shigekuni Yamamoto (Bleach) was the most powerful Shinigami to have been born in the last 1,000 years, and one of the most powerful to have ever existed.
When it comes to raw strength and fighting skill, Kenpachi Zaraki (Bleach) is one of the greatest Shinigami to have ever lived, and is nigh-unrivaled even by the most talented and experienced in existence.
Sosuke Aizen (Bleach) is an extraordinarily gifted Shinigami and is nigh-unrivaled when it comes to power, talent, skill, and intellect.
Yhwach (Bleach) was the first and most powerful Quincy to have every existed; his power is even called "The Almighty".
As the first Quincy to ever be granted powers by Yhwach, Lille Barro (Bleach) is one of the strongest Quincy to exist.
Despite seeming to be an ordinary, Quincy, Uryu Ishida (Bleach) is believed by Yhwach to possess potential that could threaten even him.
Said to be the strongest Claymore to ever have existed, Teresa of the Faint Smile (Claymore) was so strong to the point where even the strongest Awakened Beings called her a monster.
Son Goku (Dragon Ball series) is one of the most powerful and skilled warriors in Saiyan history...
...And is one of the only mortals to have ever achieved Ultra Instinct, earning him the respect of both Gods and Angels.
Born a mutant amongst the Saiyans, Broly's (Dragon Ball Super) sheer power and potential are almost unrivaled in the multiverse, surpassing even the strongest of fighters.
Frieza (Dragon Ball series) is a mutant amongst his species, a trait he inherited from his father, which accounts for their abnormally high power and potential...
...And is the very first of his race to have achieved their "Ultimate Evolution".
Lucy (Elfen Lied) is the Diclonius "queen," and is considered to be the most dangerous of her kind not just because of her murderous tendencies and great skill with her vectors, but because she is the only Diclonius who can naturally reproduce.
Medaka Kurokami (Medaka Box) is as much above Abnormals as they are above humans.
Escanor (Seven Deadly Sins) is considered to be the strongest human in the world.
While biologically 100% human, Charlotte Linlin/Big Mom (One Piece) was born with the strength and potential surpassing even some of the strongest Giants.
Saitama (One Punch Man) is the absolute pinnacle of both human and superhuman potential capability after years of training.
Jin Toujou (Shinmai Maou no Testament) is considered to be the strongest Hero, even being compared to a War God.
The 12 Heavens Blade (Chrome Shelled Regios) are the strongest Military Artists in the world...
...Alsherya Almonise is the strongest among the Heavens Blade...
...Lintence Haden is the Strongest Heavens Blade after Alsherya yet he could still put up a fight against her...
...Delbone Q. Myuura is the strongest Psychokinesist and a member of the Heavens Blade...
...Layfon Alseif was the youngest Heavens Blade and soon rivaled his former master, Lintence despite him not having a Heaven's Blade anymore.
Nina Antalk (Chrome Shelled Regios) become one of the strongest Military Artists and on par with the Twelve Heavens Blades.
Felli Loss (Chrome Shelled Regios) became the strongest Psychokinesist in the world.
Even by the high standards of his species, Kars (JoJo's Bizarre Adventure Part II: Battle Tendency) was stated to have been a genius among the Pillar Men...
...having been the original creator of the Stone Mask...
...and the sole one of his kind to become the Ultimate Being after donning a Stone Mask combined with the Red Stone of Aja.
Ryomen Sukuna, the King of Curses (JUJUTSU KAISEN)
Satoru Gojo (JUJUTSU KAISEN)
Having reached the highest caliber of Iwagakure Ninjutsu, Gabimaru (Hell’s Paradise: Jigokuraku) is a very powerful shinobi whose abilities far exceeded that of the norm.
Muzan Kibutsuji (Kimetsu no Yaiba)
The Six Greats Generals of Qin (Kingdom)
Known throughout China as the Monstrous Bird of Qin, Ou Ki (Kingdom) was one of the greatest top tier characters in the Kingdom series...
..., just by standing near him you could feel such a heavy presence
that it could easily intimidate and crush the weak-willed...
One of the mightiest warriors of the Warring States era, Ren Pa (Kingdom) is a greatly respected figure recognized by all of China as one of the greatest Great Generals in all of China.
Rin Shou Jo, the Phantasmal General of Zhao's Three Great Heavens (Kingdom)
Possessing the rare trait of being a Second and Third Generation pyrokinetic, Benimaru Shinmon (Fire Force) is well regarded as the strongest Fire Officer in the Special Fire Force...
...as he is capable of single-handley fighting and defeating aggro Infernals with his bare hands
with unparalleled skill...
Known as the strongest, bravest, and most well-known warrior throughout the world of Vikings, Thors Snorresson (Vinland Saga) was the best, if not the greatest, warrior within the ranks of the Jomsvikings, a deadly band of Viking warriors on the Baltic seas of Europe...
...being of one the very few who could best his uncle in law Thorkell the Tall, a Jomsviking commander and one of the strongest Vikings of his times, in terms of strength and fighting skills.