Theistic satanist worship satan; had only heard of those before.
i believe those are fairly rare, and even more rarely older than 15 years of age
ive seen tons of these "mature and serious" satanists tho, they make a huge deal out of how its not about worshipping satan, but still cling to the term "satanism" and insist that "satanism" has made their lives better.
while theyre at it, they of course ridicule immature people, who worship satan as a deity "oh theyve sooo missed the point!"