alright, I have been loving this story so far and have been intending to go through the ghosts to determine their likelihood of being on the team but have been procrastinating so in order that bulbipedia is giving me (kind of, im evaluating the entire line instead of each individual ghost and skipping ones we already have):
Galarian Corsola line - unlikely, Corsela did come about by sudden environmental change which the legendary birds mentioned could do but i think this is unlikely.
Duskull line - I would say probably Diya is doing necromancy and this line is heavily related to binging the living to the other side, might even be a bit of conflict there.
Yamask line - while seemingly promising at first for maybe reviving victor (the boy that died that Diya posseted) A. that would not be in line with the tone of the story B. it is heavily implied that his should fully passed on and C. Yamask creation conditions specifically include a grave and/or the death being old. this is similar for the Galarian form
Sinestea line - unlikely, their thing is mostly about the fancy cups and I don't see Kenomao having much of a fine china market, maybe in the more posh areas but from what we have seen of Kenomao so far it is a frontier region. I do see tea drinking being a possible thing due to the climate however.
Spectrier - to close to a legendary.
Drifloon line - possible depending on how child kidnaping they are but they also like humidity so maybe not in Kenomao. According to Ultra Moon Drifblim gas is made from souls so maybe.
Spiritomb - manmade in ancient times so frontier regions are unlikely to have them due to a lack of ancient humans with a large enough civilization for spiritomb creation. I could see Diya being asked to help with one later in the series when they are more known with more experience with ghosts.
Giritina - HAHAHAHAHA! No.
Litwick line - highly likely, author has already shown interest in the line and thier absolutely wack entries.
Phantump line - likely, Phantump are lost children so is likely an unfortunate part of S&R espacially because they also get adults lost looking for friends.
Pumkaboo line - maybe, while Pumkaboo are related to lost souls and bringing them into the afterlife Gourgeist kill people and Diya may take offence (especially since large ones prey on children)
Sensu style Oricorio - while probably not in Kenomao I could easily see Diya tradeing for one. Dia has already show a likeing to dance. aditionally the Sensu style dex entries are about summoning the dead and cursing opponents, both things the Diya might want to do better.
Sandyghast line - probably not in Kenomao and i don't see Diya trading for one either.
Mimikyu - maybe. I feel like DIya would get along really well with a Mimikyu, the probem is they might not be in Kenomao.
Dhelmise - unlikely, even if we see Diya do a ship rescue one would not form from the sinking ship fast enough (and i doubt Diya is going to eat an anchor for necromancy) and Diya would probably not get along well with a Dhelmise sinking ships.
Alolan Marowak - probably, Alolan Marowak would fit in quite well with the theme of the story, Diya likes dancing, and Kenomao seems to have been colonized by a warmer climate that might have been Alola or Alola like 9i am too lazy to look around the story for where Kenomao was colonized from, I just remember it was warm)
Hisuian Typhlosion - unlikely, seems to be heavily related to Hisui/Sinnoh
Shedinja - I really want to see this, aside from the amazing potential for Diya/June collaboration it is also likely one of the more interesting/profitable research bounties due to Nincada being the only Pokémon to evolve into two Pokémon that I can think of, once Diya gets more well known in the research community they actually might be commissioned for this due to her unique perspective.
Sableye - maybe, while this pokemon is rare I could see Diya encountering one if they go for a spelunking or cave rescue badge. (not needing to breathe would be incredibly useful in underground rescues because you don't have to worry as much about bad air and ghastly is probably connected to anyways)
Froslass - highly likely, there already has ben some interesting discussion about Froslass in this thread that the author has shown interest in and I can easily see Froslass being in Kenomao.
Rotom - maybe, rotom seem to already be pretty rare but I can see it happening.
Hisuian Zorua line - I really want this to happen, the zorua line are my favorite pokemon and they are surprisingly rare and common in SI fics, rare that the story is still going (none of the pokemon SIs that I follow that update have a Zorua/Zoroark aside from Hero of Hisui/Hero of a new age and I am very saddened by this) and common in fics that exist (I know of six fics where the mc becomes a zorua, thre are SIs). the lore for the Hisuian Zorua line also fits very well with the theme of the story, maybe a really stupid kid with a zorua being rescued too late or an even worse person doing it intentionally to get a ghost normal type and being stopped a bit too late.. ill stop here so half this post is not me talking about the Zorua line (I would do it and am still tempted to)
Frillish line - maybe they are probably a common reason for ocean rescue but unless Diya start flying more with ghost powers i don't think Diya will do much ocean aquatic rescue.
Golett line - maybe, probably not in Kenomao but as one of the most solid ghosts Diya might look into them to get more from her immunities while still having a solid body.
Honedge line - maybe, Kenomao is unlikely to have many swords due to it seeming to be a more recent colonization, though it's final is a very 'powerful' battle Pokémon so it could happen also as a solid ghost Diya could do something similar to what is said about the Golett line.
Contained Hoopa - HAHAHAHAHA. No.
Dicidueye - unlikely, probably not in Kenomao, its also a final evolution Pokémon.
Lunala, Dawn Wings Necrozma, Marshadow, and Blacephalon - NOPE!
Dreepy line - unlikely, it is the only pseudo-legendary ghost type so it is likely to be both rare and protected by its higher evolutions
Shadow Rider Calyrex - no.
Basculegion - probably. this is the most likely pokemon Diya would use for aquatic rescues so Diya might actively try to get one.
Phew, that took a while.
