... j2 has pretty strong "created by taboo combinations of science and magic" energy in the Saiyuki context. He's probably one of Ukoku Sanzo's experimental subjects who ends up set aside in a random spot to get in the Saiyuki party's way, but I feel like he'd switch sides pretty fast after encountering the four of them.
Jedao, having trouble mercy killing these fucks: "....oh, hm, you might actually be useful. okay i surrender. if there's not enough space in the jeep i can sit in somebody's lap"
they'd also want to constantly get into family road trip style fights in the back of the jeep about who's taking up more than their fair share of space
Sanzo would be the one saying they're not keeping him, I suspect. Hakkai would just be passive-aggressively catty about how Jedao owes them for whatever amount of trouble and injury he managed to cause before surrendering
going with Lahabrea's actual timeline instead of just "general FFXIV", Jedao is a concept that was definitely not approved for general use, but either someone decided to create one on the sly or he's the one that got created for test purposes and was deemed useful enough to not be dissipated back into aether after the testing was done
Kahl would be one of the demons lowkey possessing the revolutionaries in Demons. Or possibly Kahl is the demon tormenting Stavrogin for the sake of vengeance for his crimes against the innocent (would be extremely valid of him)
I feel Kahl could probably follow much the same script as the one I did for John, except he's some ancient and powerful species who was intentionally trapped in the black hole at the galactic centre
and when he escapes on a clone ship that got close enough he discovers the being who betrayed and trapped him is long dead and so he turns his vengeance against the Republic and/or seppies?
iwtv: Jedao One attracted the interest of extremely old vampire Kujen who erases basically all of his memories when he turns him in properly extremely disturbing 'Maker' fashion (there are also theories that he just grabbed a random kid and inserted these memories). Jedao Two instantly labeled abomination,
which isn't helped when he ends up killing a lot of other vampires and ends up being taken under the 'protection' of others (Kujen definitely has full on 'no one else will ever understand or love you) until he makes a run for it
I'm absolutely picturing one of those things where like. Extremely Dark Magic to bind an aberration into a weaponizable form requires a living victim to be Conscious For All Nine Days and Nights of being skinned and carved with bone sigils and devoured and whatnot, and Jedao One genuinely volunteers
I love the idea of Jedao as a benevolent/neutral entity in the Dreamlands or something for John and Arthur to encounter just a cool neurotic mothman dude
and J2 is a baby of a species that lives in the hyperspace lanes that the Kaminoans captured and were studying to try and enslave and possibly clone for better/cheaper hyperspace travel, and when Fives is gathering evidence of the chips and what they do he finds and frees him in the process
... and then when Fives is being hunted down on Coruscant J2 pops out of hyperspace right there on a planet and rescues him in turn, and thus the clone rebellion begins in a very different way
just a cool neurotic mothman dude