Out of all the “mortal” types of creatures (like archfey, arch fiends, demon lords, greatwyrms, etc.) or even specific characters do you think is closest to divinity. And by mortal I mean that they don’t have a divine portfolio or ideal they rule over, they don’t require faith to sustain themselves, stuff like that.

The Atropal

I wouldn't exactly call a dead godling "mortal"

i could see the Tarrasque being worshipped as a god of destruction.

Other than that, if it has a stat block then I don't consider it a deity.

Well they are just undead god fetuses.

Maybe Greatwyrms? That would be my first guess.

Modrons, specifically Hierarch modrons (all Modrons of rank Decadron or higher) are all essentially angels of Primus, despite their creature type being Construct.

That makes me think: Could an especially popular angel, like one of the aforementioned Hierarch Modrons, become a quasi or lesser deity?

I forgot how they do it but greatwyrms can gain divinity I think

Somewhat. There's a rogue Secundus (the second-in-command to Primus, the highest Modron rank outside of Primus himself) in (iirc?) Acheron who has renegated Primus and works as his "own" Primus to a colony of rogue Modrons

If I remember right it has something to do with eating and merging all their versions from different world. I might be wrong, though.

Ian gon lie he’s gonna have to go to the prime energy plane and just start over with life. He’s chopped and screwed😭😭

Dragon Ascension. That is such a raw term😭

Dragons by miles, given that if they become old enough, they become dragon ascendents, which is treated as a form of quasi deity.

And of course, bonus mention for the Modrons given that they could feasibly become Primus

Yeah, it's in some weird halfway state. I just like name dropping them whenever I feel like I can get away with it.