Gol D. Roger ushered in a new age of pirates with the revelation of his most precious treasure, One Piece. The announcement shocked the entire world and all sorts of pirates wanted to try their luck desperately. One of the many to be motivated by the desire to find the ultimate treasure is none other than Monkey D. Luffy.
At a young age, Luffy met Shanks, who inspired him to become a pirate. He set out from Fooshia Village in order to realize his dreams. He has fared pretty well so far and in the meantime, he has gathered a great crew. Several times Luffy has demonstrated that he is perfectly equipped to become the Pirate King, however, he has also been humbled several times.
10 PIRATE KING MATERIAL: Proclaimed War Versus Big Mom
At Fish-Man Island, the Straw Hat Pirates faced their first challenge after the time-skip. They faced the New Fishman Pirates, who were led by Hody Jones. It was an easy victory for the Straw Hats, who were in need of some practice after their hiatus. One of the best moments from the arc was the time when Luffy declared that Fish-Man Island was under his protection now. Despite the obvious difference in their ranks, Luffy talked to Big Mom as if he was an equal.
9 FELL SHORT: Utterly Beaten At Sabaody
Sabaody Archipelago is arguably one of the best arcs in the entire One Piece. A lot of big names were involved in the arc, including Silvers Rayleigh, members of the Worst Generation, and Admiral Kizaru. Kizaru arrived on Sabaody because Luffy punched a Celestial Dragon. Kizaru set his sights on the Straw Hats, but Silvers Rayleigh stepped in to stop him. However, this wasn't enough to stop the Straw Hats from being humiliated by Kuma, Sentomaru, and the Pacifista. Luffy was left all alone and crying due to his inability to protect his crew.
8 PIRATE KING MATERIAL: Punched A Celestial Dragon
Sabaody had a lot of great moments and Luffy was responsible was for the greatest of them all. At the auction house, Camie was being sold. Luffy and Rayleigh managed to free her, but the trouble wasn't over. Hachi who was trying to calm down was shot by a Celestial Dragon.
Luffy was bewildered by the incident and without thinking about the consequences, he punched the Celestial Dragon, which resulted in Kizaru's arrival on the island.
7 FELL SHORT: Humiliated By Kaido
One Piece is currently focused on the events that are happening in Wano. The fans have already hyped it to be the best arc to date. The main antagonist of Wano arc is undoubtedly Kaido, who is one of the Yonko. Kaido and Luffy had a fight early on in the arc. For the majority of the fight, Kaido was drunk and all of Luffy's attacks managed to make him sober. Then Kaido basically one-shot him with his attack. This showed the huge difference between Luffy and Kaido's power.
6 PIRATE KING MATERIAL: Raided Impel Down
Luffy was sent to Amazon Lily by Bartholomew Kuma. It was there he learned about Ace's execution that was scheduled to take place at Marineford. Luffy made up his mind that he was going to invade Impel Down to save his brother. He invaded Impel Down with some help from Boa Hancock. Luffy wreaked havoc in Impel Down and he faced Magellan as well. He managed to break out from the tightly guarded prison with some very famous pirates, creating another setback for the World Government.
5 FELL SHORT: Beaten By Big Mom
Whole Cake Island might have been Sanji's arc, but it was Luffy who was involved in the big fights. Big Mom hadn't forgotten Luffy's outrageous proclamation that Fish-Man Island was under his protection.
Luffy had a brief tussle with Big Mom and it ended badly for the former. All of Luffy's energy was drained and Big Mom was unfazed. Again this showed the power difference between the two.
4 PIRATE KING MATERIAL: Heroics At Marineford
Luffy narrowly missed out on escaping from Impel Down along with Ace, who was transported to Marineford. This didn't dampen Luffy's spirits in the slightest. He decided that he was going to Marineford to save his brother. He made an extraordinary entry at Marineford and teamed up with the Whitebeard Pirates to save his brother. Thanks to Luffy's efforts, Ace was freed from the shackles. Luffy gave his best to save Ace, but that wasn't enough. Still, his efforts were recognized by both Marines and pirates alike.
3 FELL SHORT: Crushed By Crocodile
No villain managed to thrash Luffy as badly as Mr. 0 aka Crocodile. Crocodile possesses the Suna Suna no Mi, which is a logia type devil fruit. The devil fruit granted him an advantage over Luffy; he managed to beat Luffy two times, which is pretty humiliating. Luffy was very lucky that he was saved, and he finally managed to beat Crocodile in his third attempt.
2 PIRATE KING MATERIAL: Declared War Against The World Government
Luffy absolutely adores his crew and he is willing to go to any lengths to save them. This was proven when Nico Robin was taken by CP-9. Luffy and co. went to Enies Lobby and even though Spandam warned them that they'd be making enemies of the World Government, Luffy didn't care. Instead, he ordered Usopp to shoot down the flag of the World Government.
1 FELL SHORT: Frozen By Aokiji
The first Navy Admiral that the Straw Hats faced was Aokiji. Endowed with the powers of Hie Hie no Mi, Aokiji is among the strongest characters in the series. Like in many cases, Luffy let his emotions get the better of him, which caused him to attack Aokiji. Aokiji demonstrated how much superior he was in strength when he froze him in an instant.