I live with my mother, who has advancing dementia and the most unreal, surreal, completely out of nowhere delusions and hallucinations. I could never in my wildest dreams have imagined the things she comes up with. And they are all horrible. My sister and I are building some kind of torture structure in the backyard to kill her in terrible ways. There are people in the house who are going to kill her. My sister puts things in her ears at night so she can't hear. Etc.
In answer to similar questions about how to handle this, many posters have offered suggestions like check for UTI, get her on medication, redirect her and so on. None of these things work. Believe me, I've tried them all. (She is on Seroquel, which probably helps to a degree; who knows how bad it would be without it?) It also doesn't work to try to tell her these things aren't happening to her. I know this, but sometimes I can't stop myself and I lose my patience way too often. At the suggestion of another poster, I'm carrying a worry stone, in my case a small glass heart. Holding onto it for dear life gives me a moment to take a breath and calm myself down when things go completely off the rails.
I would love to hear from anyone who is dealing with a combative, impossible to redirect LO who is having hallucinations and delusions that go so far beyond the garden variety "somebody stole my purse" that they might as well be from Planet Xenon. In the meantime, I am carrying my worry stone with me at all times.