There isn't one, abortion is a personal choice, people are just trying to scare you with their horror stories, it may not be for everyone, but it isn't satanic.
There's no relationship. Deciding to have an abortion cuts across all lines, and being a Satanist doesn't make you more or less likely to have an abortion.
This is a complete myth created by anti-abortion progandists. There is no such conspiracy or relationship whatsoever; it is a lie to fool the gullible.
There is no relationship between abortion and Satanism. The horrible stories you've heard are probably from anti-abortion activists and religious extremist who will create stories or spread urban legends to create an emotional response.