Well it's more like a optional side story than a chain of quests. It involved the NPC Glaive the administrator of Henir's Time and Space.

I already explained about a little plan that involved him in the past somewhere in the ooc. Basically he would be a way to allow our characters to train by having Glaive send them to Henir's Time and Space. A place outside of space and time where our characters will be forced to fight notable villains from their past in an attempt to train them. Of course Henir would have modified these "memories" of past villains and opponents to make the fights more difficult. It will basically function just like it does in the game.
There will be breaks for our characters every now and then so they can rest up and all. Because of the place being outside space and time during these breaks our characters injuries will be healed, ammo restored, gear repaired, and even enhanced temporarily if they performed well. If any of the participants get to their breaking point and won't be able to fight anymore, surrender, or just flat out want to stop then Glaive will take them out of Henir's Time and Space and give them a little reward. The farther they get into Henir's Time and Space the greater the reward.
Glaive could be introduced when the new characters (and even some of the old ones) require new training to become stronger for their next mission or whatever. Raven would be the one to most likely help everyone find Glaive as Raven is familiar with the more popular locations that Glaive "hangs out" at. These locations are in secret locations hidden out of sight in each major city in the RP. Since Glaive can control time and space he can pretty much be at almost any of his popular locations in what appears to be an instant.
This is just a little something for everyone. I have an actual story arc planned for the sequel that does involve Ran as the main villain.