You can call non-terrestrial beings whatever you like. Personally, I prefer the term "ETs". And you could maybe research how the Bible scripts were translated and compiled - then recompiled several times over centuries. It's quite enlightening to understand how the original texts were modified by mistranslations, by additions and omissions. The compilers modified the message to suit their own political ends - just as the deep state is doing right now. And bear in mind that the original writers had no concept of "extraterrestrials" or technology. Anyone who had "magical" technology allowing them to fly and zap things had to be a "god" or "angel" or "demon" because those were the only descriptions that they knew.

But you are partly correct in envisioning their "phasing in and out". However, it's probably just technology beyond our current comprehension so it seems like "magic" to us.

They are sentient, however. Look it up; it means "able to perceive or feel things". A snail, for example, is sentient. It's not human or intelligent (or a "demon") but it's sentient. :)