These are the Top Ten Strongest Characters of One Punch Man based on the manga. They are ranked based on raw strength and power against each other.
10. Atomic Samurai
Atomic Samurai, also known as Kamikaze, is an S-Class Hero Rank 4 that is the best swordsman in the entire series. He has fought many powerful dragon level villains and came out unscathed in most cases. His attack, Atomic Slash is one of the most powerful attacks of the series that leave the opponent with more than 100 slashes in an instant.
9. Silver Fang
Silver Fang is a master of martial arts that sits in the top three strongest heroes under Hero Association. He has immense skill with his “Water Stream Rock Smashing Fist” Martial Arts. Paired with incredible endurance and strength, he gets through most opponents with ease.
8. Psykos
She is a Dragon Level monster who had the telekinetic powers that are in par with Tatsumaki. Psykos also fused with defeated Orochi to become even more powerful.
7. Black Sperm
This cunning monster with the unique name went through a transformation called Golden Sperm that gave him strong regenerative and destructive powers that could defeat the Atomic Samurai.
6. Orochi
Orochi is the king of monsters and one of the most powerful villains that Saitama had to face. He had previously defeated the Half Monster “Garou”. He also survived after multiple punches from Saitama but eventually got defeated.
5. Boros
Boros is the alien villain that invaded earth in search of a strong warrior. He claimed that he has searched the whole universe for someone stronger but failed. Boros had immense energy that could destroy the whole Earth. He was the first fighter to survive a punch from Saitama.
4. Tatsumaki
She is the second rank S-Class hero that has strong mental abilities. She can manipulate any living or non-living thing with her psychic ability. She is the most powerful known psychic in the One Punch Man story.
3. Garou
He is a former disciple of Silver Fang, calls himself Hero Hunter. He has achieved a form after he broke the limiter that turned him into a monster. Garou has a near-death experience that eventually pushed him to become a monster. He is the strongest monster right now surpassing Orochi.
2. Blast
He is a mysterious hero that is ranked first among the Heroes. He has never made an appearance in the manga. He is said to have eliminated the Ninja Village that Speed O Sonic belongs to. His current whereabouts are unknown. Blast is rumored to have broken his limiter.
1. Saitama
Saitama is the main character of One Punch Man who has broken his limiter. This gave him immense strength and ability to finish off most opponents in a single punch. He is arguably the strongest character of One Punch Man.
Honorable Mentions
Elder Centipede
It was a dragon level monster that has existed for a very long time. Elder Centipede even survived against the most powerful hero, Blast. It had the size of a city and could move at monstrous speeds.
God
God is a newer character from the manga that can give and take powers from people. Other strengths are unknown but he is a strong future villain that has his influence in the monster association.