To edit a story after posting, first check if the website or app you used has an edit feature. Sometimes it might be in the settings or right next to the post. Also, keep in mind that there might be time limits or certain restrictions on what you can change.
The Dark Dark Fruit could enhance Luffy's physical strength in a different way. Instead of just relying on his rubber body, the fruit's power could give him a more menacing presence in battle. He could use the darkness to absorb attacks and then redirect that energy, making his counter - attacks even more powerful. For instance, if an enemy throws a punch, Luffy could use the dark power to suck in the force of the punch and then send it back double - strength.
His leadership style could change significantly. In the original, he leads with his heart and by example, but in a dark fanfiction, he could be more of a dictator - like leader within his crew, making decisions without much input from others and demanding strict obedience. His goals might also shift from just finding the One Piece and having a grand adventure to seeking power for more self - centered reasons, like revenge or dominance.
In such a fanfiction, perhaps Luffy's character would change drastically. The dark dark fruit might give him new powers like controlling shadows more intensely than Blackbeard. He could use it to create shadow clones of his crew for strategic battles, adding a new and darker dimension to his fighting style.
In most cases, you can. However, the availability and extent of editing might vary. Some might only let you fix typos or minor errors, while others might allow more substantial changes. Always read the platform's guidelines to know for sure.