2cave should have literally everything going against him. He isn't popular, has no story relevance, and doesn't have a unique weapon to base gameplay around. But he is also Daisuke's personal choice to bring back. That is a genuinely incredible feat considering all of the other (actually interesting) characters in the series, and it could honestly carry him to playability. Unless it was a joke, of course. Only time will tell.

Answer has a lot of cards stacked in his favor. Unique gameplay, decent popularity, and relevance to a somewhat unexplored lore avenue that is the Eastern Chipp Kingdom. That decent popularity is in a perfect middle ground of being popular enough to get votes but not nearly as much as Jam or Robo-Ky, letting him easily fit into any future season regardless of the other characters. Very very high chances.

Ariels feels like she missed her chance. Back in Xrd she was important and could have easily fit as a newcomer, but now she just doesn't feel relevant. From what we know she is still imprisoned, and I really doubt she has the drive to fight anymore now that Chaos is gone. That combined with her middling popularity and lack of a central gimmick makes Ariels pretty unlikely, unfortunately.

Chronus is a really unfortunate case. Lore-wise he is one of the absolute best candidates, having an open ended story with plenty of ways to continue. He is also just generally important and therefore any future story could fit him in easily. However it all falls apart in any other section. Chronus has no defined moveset, and his popularity is low. Worst of all he is a marketing nightmare, as he has a near identical design to Street Fighter's Q which will just confuse people. All this combined means he probably won't come back outside of a new story mode. A sad fate.

Crow is self explanatory. No popularity, little lore relevance, and we have never seen him fight (Though he likely fights like Johnny, since they had the same teacher.)

What saves him is actually the addition of other characters. If Justice were to be added, she would almost certainly be a clone like she was in XX. Since Crow was responsible for said clone, he could very easily be a background character like Delilah is for Bedman?. He could also take on that role for Robo Ky II, replacing the generic "scientist" from Isuka.

Paradigm had a lot going for him, but then was turned into a stage element. Very sad. His lore relavance is very high, especially considering his recent role in Duel Rulers. His moveset potential is also very high due to his connection to Overture. But he just doesn't have the popularity to get in. The stage element thing really seals his fate, unfortunately. They could just remove him from the stage when he plays on it, but I doubt they would have added him in the first place if that was the case.

Fanny is currently very unpopular, not particularly story relevant, and has a moveset partially being original and partially taking from Dr. Baldhead. However, I think she could very easily be added to Strive. With Faust in the state he is in, Fanny could fit into his story pretty well. That could boost her relevance and popularity, and the changes to Faust's moveset since then will make her moveset stands out a bit more. In essence, Fanny has high potential but she needs a big push. And I think that could easily happen. Her super low popularity feels more like a symptom of being in a super obscure game most people don't know about rather than actual dislike. I think she has a decent chance.

The perfect character. He has been around since Missing Link, has good popularity (and even more by riding off of Potemkin's popularity), has high relevance to lore, and has incredible moveset potential as a cross between Slayer and Potemkin. Seeing as Guilty Gear essentially only has one true grappler, a new one would be a big deal and would bring a lot of variety. Gabriel is basically a guarantee in my eyes.

Izuna has been completely absent since Vastedge, and could very easily get new story elements. He isn't all that popular however. He does have somewhat decent moveset potential at least. Izuna is probably one of the easiest "forgotten" characters to bring back.

Nothing to say, really. Super popular, has been around since X, and has been asked for since the start of the game. It's more surprising that she isn't in already.

Judgment is technically dead, but with how weird his game is they could pretty easily just say he survived somehow. Even if that did happen though, he has very little going for him. No popularity, basically zero lore relevance, and a moveset with nothing particularly special about it (his main "gimmick" is that he is the only character capable of blocking). They could bring him back but I really doubt it. It would be a cool choice, just not one I would expect on any level.

Despite being dead, Justice is very easy to bring back in the form of a clone, like in AC+R. The problem is that Justice is TOO story relevant. Her coming back is a very major event and would likely require a new story mode just so they could kill the clone. Besides that though, she is popular and serves as a very different zoner compared to other ones (even if Dizzy has stolen Michael Sword). In theory the fact that Dizzy stole one of her moves would ruin her chance, but Nagoriyuki stole Bloodsucking Universe and Slayer still joined. Anything could happen. See Crow for more details about how Justice as a clone could work.

Kliff is very dead. Very very very dead. He has been dead since Missing Link and since then has only shown up in non-canon scenarios or during time travel. From a non-lore perspective he has a lot going for him due to his popularity and unique status as a low-mobility glass cannon, but the lore simply outweighs that. With Duel Rulers' focus on time travel they could theoretically work something out, but I really doubt it. It would feel weird to have Kliff not be dead.

Haehyun just makes sense. She is the most important character left that originated in Xrd, has a fairly unique moveset, and has an acceptable popularity level. She would be very easy to include and I truly doubt we would go more than a single season without her.

Leopaldon has a cult following for their incredibly weird concept and design. Their popularity has mostly grown from people making jokes about their existence, though there are a few people that truly want them in. They unfortunately have little story relevance and their gameplay is undercooked so they lack a bit in most areas. However, Daisuke was specifically asked about Leopaldon in an interview so ArcSys is at least aware of the popularity. Perhaps there is a chance? I wouldn't count on it.

A strange case. He is currently doing forced labor on the stage New Dawn, A Future Unfolding, but could very easily just not appear when played as. Like with Paradigm though, it just seems odd to put him there at all if they were planning his addition. He has pretty decent moveset potential, but lacks any popularity. He was however the subject of an ArcSys April Fool's reveal and therefore has full key art. Because of this, he probably won't be added. As much as I would love for the joke to extend to the fact that he really was becoming playable, I just doubt it unfortunately. See my extended thoughts here.

Order-Sol is very popular and has been voted for in basically every poll. His gameplay is unique and really good, and as for lore relevance he is just past Sol Badguy. The problem is that he is really hard to bring back. He is literally stuck in the past and while they did make excuses before, I am unsure if they will again. At the very least Duel Rulers had some time travel elements, so it isn't impossible. ArcSys understands the popularity, at least. Another problem though is Order-Sol's marketability. To the unaware person he looks like a skin for Sol, and therefore he probably wouldn't sell well. Or maybe he would due to his high popularity. If anything, I think the most likely option is a new character that steals his moveset (which would have worked for Unika, but she got her own thing).

Raven has everything going for him. Unique gameplan, high popularity, and most of all a ton of story potential. We have no idea what happened to him after leaving Asuka, and have only seen him ominously standing on a tower. Very high chance chance to get in all around.

Despite being super popular, getting a ton of votes, and having a very unique moveset, I actually have a bit of doubt for Robo-Ky's inclusion. He is actively a part of Venom's moveset. Now theoretically, he could be removed from it. Venom already has a version of his throw that doesn't include Robo-Ky, and Dark Angel can just have a rocket fly in from offscreen (and if we are lucky, it would be one from Venom Rocket No.13). But the question, once again, is why? Neither of Robo-Ky's inclusions are necessary, so ArcSys had no reason to include him unless they knew they wouldn't be adding Robo-Ky. His inclusion with Venom makes a lot of sense and brought some cool interactions anyway, so I doubt they really would want to bring him back.

Robo-Ky does have the other factor of being Daisuke's most wanted choice to bring back to Xrd, but again I feel like that chance has passed.

No chance. His entire gimmick is being able to take moves from other characters, which is a balancing nightmare and a ton of extra work. In addition he isn't popular and doesn't have any story. We are not getting Robo-Ky II.

Tyr is defined by potential. His existance is confined to Guilty Gear Xtra, which no one knows about. Therefore he has no popularity and little relevance, but could very easily get it back. ArcSys just has to treat him as a new character essentially, and they could easily win big like they did with Unika.

Normally I would say that Tyr is simply too obscure, and would assume that ArcSys themselves forgot about him. But out of nowhere Tyr was included in the Season 4 Character Poll, his first mention in over two decades as he hasn't even been in GG World. Someone at ArcSys knows Tyr exists, and that fact alone keeps his chances alive. Why else would they acknowledge him?

Valentine is the most dead character there is. We actively watched her die in Overture. She never got any time travel stuff to be seen again. Jack-O' stole multiple of her moves in Xrd. Ramlethal stole Lucifero, her main weapon. She has a bit of popularity but I can't see any future where Valentine gets back in. There just isn't reason for it.

"75th PRESIDENT VARNON make playable character!"

Vernon will never be playable. Whatever popularity he may have doesn't matter. His lack of a potential moveset doesn't matter. The simple fact that he is the United States President means he can not be added. The political climate is terrible and if ArcSys tried to do this they would encounter a controversy like no other. Vernon is a story mode character and nothing more.

Zappa feels like a very obvious choice, and has a good bit going for him. He's popular, somewhat lore important, and has a super unique moveset. The only problem is the fact that he is no longer controlled by the spirits, but he could pretty easily be reworked to be controlling the spirits himself. Definitely the most likely of the XX characters.