Is this type of alien being in fact possible? If so, then don't we have to look at what we 'know' as if the alien being is in fact actual?
Yes, it's possible. We could be in a simulation, which just pays special attention to details, when it needs to fool us. You get into this kind of problem real fast, when believers take consciousness altering drugs, such as DMT and LSD. People believe what they see on the trip is true, and that consciousness comes from the plane above us, because it could not exist inside our brains. If what they saw on the trips was true, then the world is set up to fool us, because there is no way for our brains to evolve, such that they can come in contact with this consciousness outside our apparent physical self. (It would have no use to evolution, and if it did, then lots of processing power could be offloaded onto the spiritual plane above us.)
It's like a computer game character slicing his head open, and finding nothing inside; he has to come to the conclusion that something outside his brain is doing all the real thinking, and creating his self. However, in a simulation which is set up to fool us, some slushy stuff would be put inside our heads, to give us something plausible that does the thinking. When we developed super MRI machines that could analyse the function of the slushy stuff, and find out how fake it was, then the simulation would have to either finish, or get more complicated.
Being totally fake, a simulation would detect that you were about to smoke DMT, and give you a fake experience. Unfortunately, once you start down the fake rabbit hole, then everything could be fake; and the only thing that made us think there was a rabbit hole, was something fake. In this case, the fakeness of it all, is an indication that it's all fake, but gives no clues to what isn't fake.
If you can think of a way for our brains to evolve, to connect with another spiritual plane, which does all our consciousness, then you can make a model where it's not all fake. Too many permutations.