Based on this type of stalker, and your previous relationship with him, he’s doing it for control. It’s a power struggle that you “won” by ending it. You can’t end it; he has to. You ending it is the rejection that this type of stalker just can’t handle, because his sense of self and self-esteem is wrapped up in you.

You really should take measures to protect yourself. This type with this history is the most dangerous. Not to scare you, but rape, and a lot of times murder too, is common among the domestic type stalker; even if you’ve never been physically, or otherwise, abused by him.

If he believes you have powers, then wouldn’t he think you’d be able to make him stop, too, or do something to him?...

The chances of this type of stalker stalking more than one is slim. It’s usually stranger stalkers who stalk more than one at a time. Stalking is time-consuming behavior and requires a lot of involvement; so it’s not too easy for someone to stalk multiple people and put the same effort in. That doesn’t mean it’s not a possibility, but highly unlikely. Your type is also unlikely to shift his focus to someone else until he is either locked up, dies, or gets his control back in some way.

Protect yourself. Get outside help!