Devils video in the style of your Undead videos.

Or perhaps just fiends in general. Demons and Devils both have great potential but cults are hard to wrap your head around.

In campaigns that prominently feature both devils and demons, they tend to blend together as evil beings from another plane. How would you make them unique from each other? Also how would you make demons more interesting, because while devils have contracts, demons just seem like mindless ravening beasts.

Another thing that intrigues me is the metaphysics of demons and devils. Would being from different planes make them really alien to us, or would they be like evil humanoids albeit far more powerful because they have the same souls. How do devils and demons even form, like what is the connection between souls and alignment. If people know heaven and hell are real, does that change how they behave? And finally, when roleplaying a devil or demon, how much influence does alignment have over them? What does a lawful evil or chaotic evil plane even mean, is the very ground evil? How do demon and devil societies even function when everyone is evil?

Sorry if this is a lot, its just that the blending of extraplanar creatures with biblical elements of evil souls going to hell is kind of confusing.