I'd be surprised if the target was Zeke since he's with the gubmint and all. They're going after bounties, right? Subjugation targets.
I'd bet he's looking at the bounty for the leader of that rebel group from that arc awhile back. I forgot the specifics since it's been awhile. The guy in charge of that shanty town where Lorem went apeshit.
@Arumir Technically Zeke is still working for the Human Government, so he shouldn't have a contract out on him yet. It's either the Aqua-Demon Boy that's friends with the cast, or the one of the leaders of the Demon faction in the exclusion zone.
Yeah I'm not buying that and it doesn't look like Merii is either. If the humans find out how demon powers work they'll likely just upgrade the anti demon weapons and wipe them all out.