Idea #5 (One Piece & Sword Art Online)

This story is a mix of Sword Art Online and One Piece.

The only way to win is to reach Raftel, the island that has the "one piece" from whichever faction your in. Everyone starts out in one of the Blues (East, South, North, West).

Those factions include:

Revolutionary Army, Pirates (Yonko, Your own group, or a group that has been previously created; Alvida pirates), World Government (Cypher Pol 0-9), and the Marines.

Certain characters are not included (Monkey D. Luffy) because they are "destined" to go their if you join them.

They can use the resources of the faction that they work to join, to get closer to Raftel, but on each island there is a challenge (boss fight/event) that they must accomplish to get to the next stage.

The level up system is also more in line with a regular RPG, but there are a few classes to choose from (can be expanded upon) like swordsman, sniper, brawler, etc. The only way to get very unique classes is through your faction, a devil fruit, and a tutor.

Devil fruits give a complete ability tree in regards to their fruit, that is separate from the main ability tree. You can have a devil fruit and another profession, but you get the same amount of skill points (unless you unlock more through achievements and such) for both classes, so it can actually hinder your growth.

There are main story line events through doing Luffy's route. You get higher rewards, but you have a larger chance of meeting over leveled enemies that can easily wipe out your team.