I've seen demons that look like normal people.
I hope your joking! Did you know any of them?
Not yet. But I have been keeping an eye on everyone I know.
Demons are not real if you think that there are demons posing as normal people then you are experiencing delusions and should contact a mental health professional as soon as possible. With the right medical help you will stop having delusions and will be able to perceive reality again.
The universe is toxic and only I can understand it.
This seems like a lot, it worries me you really seem to believe this to be true.