3-MONKEY D. LUFFY
Luffy is the son of the Revolutionary leader Monkey D. Dragon, the grandson of the Marine hero Monkey D. Garp and the captain of the Straw Hat Pirates. He currently has a bounty of 1,500,000,000 Berries.
After consuming the Gomu Gomu no Mi, Luffy’s body became like rubber, giving him the ability to stretch and attack long distances. Having undergone intense training for over ten years, Luffy is now able to supplement his stretching powers with immense strength, agility, and creativity in combat.
He has also developed several peculiar methods of combat as time passed, adapting new forms by manipulating his elastic body(Gear 2 and Gear 3) and using Haki in conjunction with the fruit’s powers (Gear 4).
After pushing his Kenbunshoku Haki to its peak during his fight against Katakuri, Luffy gained the ability to see into the future to a limited extent.
Luffy has advanced his Busoshoku Haki, allowing him to project it from his palm as well as progress even further by destroying objects he touches from the inside at will.
During the Battle on Onigashima, he advanced his Busoshoku Haki to where he could hurt Kaido using his hardened Gear Third, whereas he previously could not, even while using Gear Fourth.
Anyway Haoshoku Haki is Luffy’s main expertise concerning Haki.
While fighting Kaido on Onigashima, Luffy came to understand that he could use his Haoshoku Haki to infuse his arms and legs and exponentially increase his attack power, becoming one of only a handful of Haoshoku users known to achieve this advanced technique. With this new skill, Luffy dramatically enhanced the destructive capabilities of the advanced Busoshoku Haki attacks that he recently learned, becoming capable of striking Kaido with immensely powerful blows without even making direct contact with the Emperor’s body.
Not long after, when Luffy and Kaidou clashed again, the two of them split the clouds in the sky with their conflicting Haoshoku, a feat previously only seen achieved when two of the Four Emperors fought each other. This may indicate that Luffy’s Haki has ascended to the same level as that of the strongest pirates in the world.
2-MONKEY D. GARP
Garp is one of the most powerful characters seen in the series so far. Alongside Roger, he fought and prevailed against the very powerful Rocks Pirates , which consisted of three future Yonkos, earning him the epithet of “Hero of the Marines“.
He is known for cornering and fighting Gol D. Roger many times. Roger also stated that he and Garp had almost killed each other on numerous occasions. As another true testament of sheer power, Garp defeated and nearly killed Don Chinjao in the past with a single punch, whose bounty was worth over 500,000,000 Berries in his prime and was said to be able to split a continent with a headbutt.
The extent of Garp’s power and fame is evident round the time of the Battle of Edd War, three years before the future Pirate King died. It was revealed that he was offered the promotion to the rank of Admiral more than once, but repeatedly refused the promotion.
Despite his advanced age, Garp still posseses tremendous strength.
1-MONKEY D. DRAGON
Monkey D. Dragon is the infamous leader of the Revolutionary Army. He is the World Government’s greatest enemy, and is the most dangerous and most wanted man in the world.
Dragon is already a powerful threat in his own right, as well as having powerful subordinates such as Sabo, Ivankov, Bartholomew Kuma, and Inazuma who are in comparison, lower in rank. This only speaks volumes of his true power.
Dragon has been shown to control the air and even lightning, just whether in general. He probably has the strongest Zoan Devil Fruit in the series.
When he was mentioned at the Summit War everyone froze, just at the thought of Dragon. Everyone is scared of him. He is at least Yonko level. Maybe the strongest character of the series.