Several things happened with Luffy following his attack on Saint Charlos. The World Government didn’t raise his bounty immediately after hitting the Celestial Dragon, but rather that and his subsequent actions caused his bounty to be increased. At first it was 300,000,000 Berries, and then it became 400,000,000 Berries.
During the Sabaody Archipelago arc, Hachi was shot by a Celestial Dragon. This infuriated Luffy; he had only one thing in mind, and it was to make the Celestial Dragon pay for what he did.
The celestial dragon shot Hachi because the celestial dragon just bought a mermaid slave, who is friends with Luffy and Hachi. Luffy loses his cool, and does something that no one ever even dreams of doing and punches him.
40 years ago at the God’s Valley, many of the Celestial Dragons and their slaves were slaughtered by the notorious pirate crew called by the Rocks Pirates led by Rocks D. Xebec and his subordinates ( Charlotte Linlin, Kaido, Shiki and Edward Newgate).
What does Dragon think of Luffy?
When Dragon watches Luffy fighting Warlords, attacking Marineford (yes for ace of course) and Enies lobby; Dragon watches him grow up into a man who exceeded his expectations. We don’t know anything about his past, but he’s shown that he has extreme compassion towards the oppressed and suffering.
Another popular question is “Is Dragon in love with Luffy?”.
As such the further the show goes on Dragon’s love for his son only continues to grow as Luffy shorts the world government at every step. Dragon may be a soldier and Luffy a pirate, but both live outside the law and have similar principles and strong moral codes.
This begs the inquiry “What would Dragon do if Luffy died?”
If Luffy dies at the hands of the World Government and Akainu, Dragon’s initial reaction would be shocked, disbelief. He might speak out loud after a long pause “it can’t be true”. Then after another pause start gently crying, then yelling in anguish and lash out and destroy something.
Doffy was a skilled fighter with awakening and immense experience. Luffy beats him with his newfound gear achieved after training with baboons in a Jungle. That’s a bit of an oversimplification, sure.
Another common question is “What is the best Luffy scene of all time?”.
The Fishman Island arc has one of the most iconic Luffy scenes of all time. In this arc, Luffy and company had to face the New Fish-Men Pirates, who were dreaming of taking over the world. The Straw Hats had to take on 100,000 fish-men and beat them in order to stop Hody.