He's just pure darkness, but the fact he can feel everything that Ventus felt and Ven's own heart fracturing and how the final fight in BBS goes, we also have proof that Ventus is involved in Vanitas.

He chose to be a villian, but did he really have a choice. Both Dark road and Character files have confirmed some aspects of the novel backstory. (Also Kingdom hearts has a series of misconceptions usually brought on by the adults. Yen sid and Ansem about Nobodies. Odin about Baldr. Who's to say Xehanort is also not mistaken.)

There is so much more. Why are there two Vanitas chess pieces? Who the darkness inside Ventus really was during Re:Mind? ( I personally don't think that's Vanitas. I don't see a lot of design motifs matching.). The novels implying he has Ven's Ux memories.

But the best is..

Where even is Vanitas right now? Ansem the wise has implied that Sora's darkness can trap hearts in it. But then what's in Ventus? Why does his Character story use emptiness as a place beyond light and dark?

Riku is. Sora is a false king.

Ventus deserves a break. This being of light is such a sweetheart, and he always wants to help people. He loves his friends so very much, so so so very much. He always wants to do the right thing. While he knows how to fight, he’s a pacifist at heart. One person said of him that he is “just over all totally husband material!” What do you say? Do you want to spend your life with him?

I wasn't going to say anything because I was sure someone else was going to bring it up, but 2 Darknesses escaped Data-Daybreak Town - Ventus harbors one in his Heart which we assume to be Vanitas but for sure appeared in KHIII Re:Mind as Dark Inferno χ

Well then clearly, the one who fought Luxu either entered Luxu's body, or it escaped, which might explain why we fight the OG Dark Inferno in the Keyblade Graveyard in standard KHIII as a secret boss. 🤔

We had big brain energy in the server today.

Ok ok ok so I am not caught up on UX and I am neck deep in my own AUs but from what I’ve gathered we’ve got a vaguely human shaped coalescence of essence who seems to be actively manipulating(/possessing?) a ten year old (and also maybe Ava? Unclear) for its own as of yet unknown ends.

I have a few questions, comments, and concerns about that setup.

Question: why Ventus? This might be something that’s been answered in canon but unfortunately I got stuck and fell out of the game. What makes Ven so especially useful in this scenario? He’s in like the 4th grade. I was practically useless as a 4th grader. Could Darkness not do whatever it is they’re doing with someone older?

Question: Why was Xehanort unable to possess Ven? He’s explicitly using the power of darkness to pull his shenanigans. He needed Terra to have more darkness vibes to possess him. Darkness is pulling bullshit with Ven in UX. Did Ven's trauma simply reject the vibes somehow? He needs to teach me his secrets so I can survive the holiday season.

Comment: I don’t know if this is still up for consideration but I’ve seen people suggesting Vanitas and Darkness might be the same character. I don’t personally think so, because of various character reasons. Vanitas very explicitly sources himself from Ventus and Darkness seems to be completely external. If Vanitas was Darkness he’d probably have mentioned something that wouldn’t track with him originating from Ven's heart, and I’m pretty sure he hasn’t yet.

Comment: I have no idea what the point of Darkness is, narratively, beyond to break the murder mystery and give us another twist. Did they talk to Maleficent once? I don’t remember what about. They had nothing to do with Strelitzia's fate or any of the new union leaders or anyone until suddenly they did, and tbh I was kind of disappointed. Did anyone call that? Did anyone say "oh, of course it was with vague shape! That makes other things add up!" Not that I saw. There are times and places to break storytelling conventions but tossing a previously unrelated character who was practically a nonentity beforehand into a murder mystery isn’t it imo

Concern: Darkness might end up being another new character. I hope not and if it happens I’ll scream.

What’s that? Oh it’s just the sound of me losing my shit and crying because Ventus I’m in the same room Strelitzia died in and we have no idea if this is related to darkness or not and I have a sneaking suspicion my theory might actually be true and if it is...