Eiichiro Oda has already hinted at the new power-up of Luffy in One Piece.

SUMMARY

The Five Elders altered the entire course of the war, not only preventing Dr. Vegapunk from departing the island, but also demonstrating that Luffy’s Gear 5 powers are insufficient.

As a result, Luffy requires a power-up that may give him abilities greater than Gear 5.
Eiichiro Oda may have dropped indications implying that Luffy may follow in the footsteps of a Hindu God and obtain his most powerful power-up in One Piece to date.

Ever since the Five Elders stepped on Egghead Island in One Piece, things have gotten worse for the Straw Hat Pirates. The Five Elders have changed the entire course of the battle and not only stopped Dr. Vegapunk from escaping the island but also proved that Luffy’s Gear 5 abilities are not enough.
Five Elders in One Piece | Toei Animation
If Luffy and his crew manage to escape from the island by some miracle, it will not change the simple fact that Luffy’s abilities are insufficient for the next stage in the One Piece story. While the Five Elders are some of Luffy’s most formidable opponents, the forthcoming antagonists will be even more powerful.

As a result, Luffy basically needs a power-up that could give him powers better than Gear 5 and enable him to take down the Five Elders as well as all future adversaries. Eiichiro Oda may have planted hints indicating that Luffy may follow in the footsteps of a Hindu God and acquire his most formidable power-up in One Piece to date.

Eiichiro Oda Has Established Luffy’s Connection to the Hindu God Hanuman

There have been multiple occasions where Eiichiro Oda has proven that Luffy’s character is inspired by the Hindu deity Hanuman. The first connection that has been established is his name. Luffy’s full name is Monkey D. Luffy and Hanuman were Vanara, a race of monkeys from Hindu mythology that dwelled in the forest.

Another connection between Luffy and God Hanuman is their appetite. Lord Hanuman had a big appetite, just like Luffy, and both of them love eating food. In fact, Hanuman’s appetite was so epic that he once flew to the sun and tried to eat it because he was hungry and he thought that the sun was a ripe fruit.
Gear 5 Bajrang Gun | Toei Animation
The final connection between Luffy and Lord Hanuman is his attack and physical form in Gear 5. Luffy’s strongest attack in Gear 5 is called Gomu Gomu no Bajrang Gun, which is inspired by the alternate name of Hanuman: Bajrang Bali. Also, Luffy can grow or shrink in size according to his will, just like Hanuman.

Luffy’s Connection to Hanuman Might Help Him Get a New Power-Up

Recently, Dr. Vegapunk explained the indefinite power of the Mother Flame, an energy source that is being used by the World Government. It is quite similar to the sun. Therefore, there is a chance that, just like Hanuman ate the sun, Luffy might eat the Mother Flame which may help him get a stronger power than Gear 5.
Gear 5 Luffy in One Piece | Toei Animation
According to Hindu mythology, when Hanuman tried to eat the sun, he was struck by lightning by the king of Gods, Indra. This resulted in Hanuman’s father taking away all the air from the universe. Thus, to rectify their mistake and convince Hanuman’s father, the other Gods granted Hanuman new powers, making him one of the strongest Gods in Hindu mythology.

As it is already established, Oda has taken inspiration from Hanuman for Luffy. Therefore, there is a chance that, just like Lord Hanuman, Luffy might eat the Mother Flame, which will in turn grant him a new and final power-up.