My idea is for Jak and Daxter to somehow end up in the world of either Danmachi or RWBY the setting for Jak will be after Jak 3 so jak will have all the weapon mods and all dark and light eco abilities and to get ammo for his weapons it would pertain to how he gets into the world or for Danmachi maybe it could be part of his falna abilities like the ability to manipulate eco instead of magic to create ammo or he works with Hephaestus to recreate his ammo same idea for if he's in the world of remnant Ruby helps him recreate his ammunition. For the way how he gets into the world I was thinking along the lines of either similar to how Jak 2 starts Jak and Daxter goes through a precursor portal ends up in either the world of remnant or Danmachi and this leads me to one of the ideas for how he stocks back up on ammunition like because of the previous incident this time one of his friends helps to create an interdimensional wackadoodle communication device so they can stay in contact no matter where he ends up although he is trapped in the other worlds for the time being they are still able to use the portal and the device to send ammunition care packages or even vehicles like from Jak 3 or Jak X or you can choose your favorite vehicle from any of the series and you use that vehicle while going through the portal another idea is that at the end of Jak 3 the setting at the end is different the precursors ask Jak if he was willing to help other planets that are in trouble this could lead to a multi crossover fanfic where Jak and some of his friends can all travel with the precursors and travel to different anime or game worlds you get the idea and help out those people that were in trouble.