please read!!! what would you do if this was your family member?

i don’t even know where to begin on this. my brother is almost 30 years old. not to be mean but he’s always kinda been a “low life”. he’s never lived alone, very isolated, works a part time job, never hangs out w anyone, no car/license, plays video games all day. anyway, my mom brought to my attention that my brother makes a lot of stuff up. he claims that he has a bunch of girl friends and i guess he went to school with them. these girls are extremely attractive, could be models. when he shows us these girls the pictures seem very professional or like they were taken from tumblr, pinterest, etc. we’ve tried to find these girls on social media, no results. we’ve looked them up in his school yearbooks, nothing. we’ve looked up their numbers, they come back as textfree numbers. he also claims to be in a band. he’ll play us all these songs that they either wrote or did a cover of. i was completely baffled my brother could sing until one day my mom said she thought one sounded familiar and she found it on youtube. he doesn’t drive and never leaves the house but yet he’s always coming out with new music to show us. he still lives at home. well he told my mom he has a girlfriend & that she comes and stays the night every night (we have cameras outside and there is definitely no girl coming over). a couple years ago i guess he was having twin girls but his girlfriend lost the babies due to a blood disorder. i believe she was about 4-6 months and far enough to have some kind of memorabilia of the babies. i’ve seen one ultrasound pic and it’s from my brothers phone and it looked like it was downloaded. i asked if he had any other kind of memorabilia such as more ultrasound pics or maybe ashes and he said no so i just let it go. he was apparently engaged before that and proposed to the girl at the top of a mountain. there is no pictures of him and this girl. no engagement pics. no nothing. i guess she was shot and killed during their engagement. my mom had no idea he was even dating anyone until he told her that she died. lastly, he’s only ever told my mom this stuff but she told me because she doesn’t even know what to do anymore. i guess he’s part of a “coven” and him and these “girl friends” all “meet up” at night and do whatever. he says he is the lord of purgatory and one of the seven angels? (sorry if that’s wrong i’m not religious or into that kind of stuff). he also said he has been to the moon, atlantis, a different galaxy, you name it he’s been there. in this coven he also apparently has children (1 with each of his girl friends). there’s more details to everything but he mainly tells my mom all of this. i think he knows i’m a little more blunt and likely to question him. i haven’t said a word to him because idk how but it’s also getting out of hand. i have high suspicions that he’s schizophrenic or atleast very mentally ill and delusional. i’m not a psychiatrist but i know these are not normal things. making up people, friends, stories, and having a god like complex are signs of mental illness. what would you do? saying something could set him off but not saying something if he needs medication could also be dangerous…