So fun fact, this post has lived rent free in my brain for literal actual years now and grown like a slime mold in the back of my brain since
Some details may need editing if I ever rewatch for the purposes of having the facts straight but like
Part the first aka tying some loose threads between canons. I.e. uuuuuuh the dragon pendants in Phantom.
Two pendants that allow one to transform into dragons but only when in A State (Canon to DP)
I have half a memory of the ability of the Dragon Council (ADJL) being able to remove dragon powers for Plot Reasons and threatening to take Jakes(??? Probably it's been a decade+ since I watched the source material)
My conceit for the tie here was "what if the pendants were the result of some non dragon magic users attempting to harness dragon powers without Proper Dragon Rituals so the methods are. Dire."
Resulting in Dragon's Eye Pendants. Sourced Organically, but Not Consentually.
Now made with Actual Dragon Eyes! (May or may not contain whole trapped souls of the dragons in question.)
Yeah historically everyone who heard about this after the fact was very into either burning everything involved so it could never be done again (98% of the magical world) or reaaaaally wanted to get their hands on the ritual info (tooooootally not to replicate it nooooooooo. Purely for academic purposes they swear. :))))) )
Danny finds all of this out in the exposition prequel where he digs up info on the pendants on Dorathea's request and finds out abt it and subsequently awakens/half jail breaks the two dragons in question
Still tied to the pendants but the elder/prototype dragon's Whole Job was defending the kingdom and it's people anyway so they're perfectly chill staying with the Princess (Heavily picturing Lesbian Elder Sister Knight Type)
The younger of the two was a sickly studious sort who is very interested in going along w Danny to college and frequently passes as the shade of a one eyed scraggly little cat that hangs around reading over his shoulder or up on a shelf
Tail end of Just The Exposition Prequel Dear Golly is Danny making mention of applying for colleges in/near NYC because of it being a magical hub he wouldn't have to deal with someone territorial pitching a fit bc of a Ghost moving in even temporarily
Definitely not gonna come back to bite anyone noooooo :)))))))
Anyway part of the A Plot for the Actual Crossover would be that even Having A Dragon's Eye Pendant is a major red flag esp because Danny's weird but like. Human passing weird (as much fun as I think him being perpetually off is, in this particular case I think there being a strict delineation between human and ghost forms would aide the shenanigans in this fic specifically. He's so human-normal your honor. Why does he have an incredibly powerful magical artifact?!)
And actually.
A-Plot- Someone is actually poking around trying to find the pieces of the ritual. Danny is the obvious suspect especially because I think a fun option for how he and Jake meet is either a Mythology course or a series of lectures on mythos. Part of this plot would feature A Specific Book. There are two well known editions-one that is still in Normal Human Hands (Library copy), one that is solely in Magical Hands. There's actually a third copy that includes the name of the accursed ritual maker for the Dragon's Eye Pendant. It's only found in Ghost Libraries because all the copies with the ritual maker's name were burned. So they couldn't be summoned :) for details. Which definitely won't come into play later :))))
A-Sub-Plot- Because the ritual also traps spirits for eternity it's actually part of Danny's job as spirit bridge/Ghost Prince/etc to make sure this doesn't happen again so he's also on the tail of whoever the clown trying to do this is. And his classmate Jake is acting real fuckin weird about his necklace and where he got it.
Which sucks because ignoring all the magical tension they get along really well.
(One fun interaction idea is at the end of a long weekend Danny's scrapping for tech to alter/cannablize for parts at the family secondhand shop and while changing forms hides his magical signature. A weekend haunting Amity or the ghost zone leaves. Traces. Fu dog is just like "Jakey, that kid reeks of death magic.")
This would need to be so gd long to do the mystery of it well and I'm just. Not that kinda writer.
If anyone wants I'll add further spark notes on plot beats that I keep picturing
