So this is probably to see if Roger and Luffy have the different or same fate and it will led to different conclusion in the end of One Piece.
Number 1 – Luffy’s health.
Roger had a disease from the start of his journey. He knew from the beginning that he isn’t going to have a long life. That’s why they took Crocus with them in order to keep Roger healthy and alive till the end of his journey. He also surrendered himself to the marine just because he was going to die anyway because of that disease.Where as mentioned by Luffy that he never had a fever in his life before and from the starting of his journey up to now. He doesn’t seems to have life threatening disease which can a barrier for him.
Number 2 – Ancient Weapon Poseidon
As Roger was from the generation of Queen Otohime. Poseidon wasn’t born at the time of Roger. Poseidon was born as Shirahoshi 16 years ago which was long waited by sea kings. What Roger probably gained was only the location and the knowledge of truth of Noah and Joy Boy .
Where as, Luffy is prophesied to guide the Poseidon’s power in such a way that it will bring the change to the whole world.
Number 3 is also a another Ancient Weapon: PLUTON.
Shiki claimed that Roger knew the location of the Ancient Weapon, but hadn’t said which one.
Roger had no desire to rule the world, no matter how much pressure Shiki have put on Roger, he rejects Shiki’s offer to use it to conquer the world.
I believe it was Uranus not Pluton and Poseidon .
First, as i mentioned previously Poseidon wasn’t even born at that time.
As for Pluton i don’t believe that it was Pluton because If Roger knew about the Pluton in Alabasta, then why didn’t Cobra mention Roger in the Tomb of the Kings?
Why did Cobra never mentioned about Roger during his execution or in the series
Instead, he was more worried about the ‘terrible age’ that would begin with.
It is possible that Roger would have used VOICE OF ALL THINGS to know about Pluton.
But this is highly unlikely and very far-fetched because he wouldn’t have known the secret entrance to the underground of the Tomb to start with and even if he would have known I highly doubt that he would have entered the tomb without Cobra knowing about it.
Where as, Nico Robin read the Poneglyph and knows where in the Alabasta Pluton is located. She lied to Crocodile because she wasn’t interested in the weapon and just wanted to know the history. But if in the future Strawhats required all three Ancient Weapons, she knows where to find it .
Number 4 – Ohara’s knowledge as Nico Robin.
Rayleigh clearly mentioned that “They were not smart like Ohara’s people the only way they could have known about the ancient history and decipher the Poneglyph is because Roger could hear the THE VOICE OF ALL THINGS”.
And that’s why Roger has to revise his journey several times even after reaching the end of Grand Line. Roger had to revise his course greatly which took him great amount of time. As Rayleigh said we were too impatient maybe Luffy will reach to a different conclusion.
Where as Luffy with his ambition and “VOICE of all things” also have Robin with him who’s dream is to reveal and know all the history of the Void Century.
Number 5 – Revolutionary Army
Now the only reason why Luffy broke out of Impel Down is because is because Ivankov find out that he is the son of Monkey D. Dragon the leader of the Revolutionary Army and agreed to him.
Also Sabo the 2nd in commmand of the REVOLUTIONARIES is the brother of Luffy. It may not look like but when the great war will break out Luffy will get an enormus support Dragon and Sabo against the World Government.
And that’s the reason why i believe Luffy’s fate is different from Roger. What Roger achieved as a Pirate King was to understand the meaning of “WIll of D” and the true history and that’s why he choose to pass it down to the next era. But Luffy will be able to do the undone and will bring the great change in the World.
*Theory by animelover421