Runeterra's Demon's : Shin Megami Tensei anyone?

I became very interested in Shin Megami Tensei when I played Persona 5 last year. I studied other games and and things related to the series. With Runeterra now having it's very own variation of demons a curious thought came in mind: the many different types of demons Runeterra is home to.

Even though Eve and Tahm can be considered part of the seven deadly sins trope, I would like to exclude them from that fact to simply create more diversity in the matter. After all, a demon also appeared in Shen's story and he fights them often. I don't think all the demons are tied to that. But what if the demons of Runeterra were in some form like the ones from the Shin Megami Tensei series?

And what I mean by that is there is some archive or religious readings that documents this species? I thought it would be pretty cool. I kinda hope Swain's new lore gives us a little more insight on the matter.