As I scroll through warhammer lore videos, i keep seeing referance to a 5th chaos god existing. Im not talking about the one in legal limbo, but i do see three characters mentioned as if they already hold the position; The Dark King, Vashtor and the Greater Good. Have any of these charachters (entities really) achieved that throne or are people just trying to incept their fan ficton into reality?
The Emperor was to become the Dark King, was ascending to become a chaos god during the fights on the Vengeful Spirit at the Siege of Terra, because he thought it to be necessary so he could defeat Horus. However, he was confronted and talked out of it by Ollanius Persson, Garviel Loken and John Grammaticus. Luetin09 published a good essay about this.
Vashtorr (two ‘r’ because Vashtor with a single ‘r’ is a Salamander Space Marine) is a Daemon, not a god.
The Greater Good isn’t an entity, it’s the founding principle of Tau society. I’ve read about a psychic manifestation of this, but since Tau are said not to be psychically perceptible in any way (unlike humans who are almost all at least latent psykers)(although ethereals are rumered to use a psychic gift to rule over Tau), a Tau warp entity is highly unlikely. There are rumors but no evidence. And even if Tau’va was a warp entity, that wouldn’t make it a chaos god.
The Greater Good manifestation, which is explicitly a minor god, was caused by humans converted to the Tau cause and was witnessed during the 4th sphere expansion. This is from War of Secrets.
Vashtorr isnt tied to any gods, and he’s a daemon not a daemon prince so he can’t be chaos undivided, so technically he is a minor god, as all daemons are just splinters of their god. Belakor is a daemon prince of chaos undivided for example.
Interestingly enough Fabius Bile is becoming a chaos god because the people he has created worship him. See the Fabius Bile trilogy.
There are also the Eldar gods like Ynnead are full blown chaos gods themselves though obviously not as powerful as the big 4. The big 4 have never been the only gods in the setting just the most powerful and influential.