creating planes of existence ?

Hi, I'm sorry if this subject has already been covered. I've already searched Reddit extensively but haven't found any satisfactory answers, so I'm giving it a shot.

Does your worldbuilding contain planes of existence/immaterial dimensions (only accessible through consciousness, or inaccessible depending on character type, etc.)?

In my worldbuilding, I have several immaterial dimensions, but I'm not entirely satisfied with them. In fact, I only have four, the two first ones, i’m okay with it, but the two others are very binary (light, good; darkness, evil).

The immaterial dimensions are important; they support several plotlines, I can’t do without it. but I think I could develop them with more nuance.

I really want to write something about evil representation beings facing good representations.

I wanted to create a kind of demon, and "guardian angels" (even though the term annoys me) — because I like the idea that some protagonists are not human and live for millennia (their relationships, emotions, memory, etc., are different from mortal protagonists). I wanted to explore this actually (just like Doctor Who, for the true nerds)

The problem is that in my research I have found that "daemons" come from ancient Greece and are not inherently evil, but I really want to create two universes that exist like two sides of the same coin.

i know they don’t have to be light x darkness, i just don’t know how to nuance it. i’ve read some mythologies, articles, forums. i’m trying to watch others fantasy worldbuilding in order to see if i could adjust anything with a new perspective, but i don’t get a new one (i hate this sb)

anyways anyone faced something like this ? sorry it’s a long vent, i’m stuck and frustrated