you found this an amazing story? whatever, not gonna judge. [side note, you can't swear in the forums, you could be gagged]
i think it's just a story. i'm not a Satanist, so i can't help you too much, but i think he's making this stuff up. first, where did you meet him? if online, i'd avoid him, it'll probably end badly for you. second, while i don't study Satanism i don't think the devil appears before you with a contract, a sexy demon, a new car, and a bag of cash. i think that's more of a Christian view of things. while, yes, you can meet a demon, and there are some that are sexual demons, i don't think becoming a Satanists in this guys secret brotherhood [which i love how secret society members love to brag about how they're in a secret club] will make you any different. i think the only difference would be the group has less to do with spiritualism and more to do with kidnapping people, which last time i checked isn't Spiritual Satanism.
if i were you, i'd research it, the claims and the group, it may be a 'secret' brotherhood, but you might be able to find stuff on, or similar to, his claims about his branch of Satanism.