I want to add a title menu option to an RMVX game called "The Lost Pages" that would choose a save file, and then warp the player to a certain area, no matter where they last saved, but would only appear after a certain switch was activated. If you need more detail on what it would do, then look in the spoiler below.
It would have mini quests that would be unlocked after beating the game that would unlock certain things in the main game. One, for example, would be an area where you could fight against a stronger version of any boss in the game. If you need more detail, saving would be disabled for the duration of the quest.
If you need an example to base it off of, then try any installment from the Pokemon Ranger series' Ranger Net Missions, if you are familiar with them.
Please and thank you!