Yeah, that pretty much seemed like what happened to us. My friend would have the mobs, and I'd walk a bit closer, and they'd be on me in a flash, no matter what he did. Our issue in Cassiopeia Hollows was before the merge, but after the accessories update, so maybe the new accessories are wonky in certain situations? We've never had this issue before, on the same classes, and I know he got himself a lot of new +enmity accessories.