I've been blue-invading people in NG+ today, and something weird happened. When using the blue eye orb, it's a bit random if you get in your local area or some other area. I used it in No Man's Wharf and got summoned to Belfry Sol, where the host was already invaded by two grey phantoms. I could hurt the grey phantoms and they could hurt me, but we just hunted down the host. 3 invaders vs the host has to be a really shitty feeling for the host.
It's boring when people rush through the boss mist when I invade someone, but at least I might be able to kill them while they try to enter. I have to invade more in the areas where you can't easily enter the boss room, Heide's tower is too easy to rush through.
So in other words, I will have to progress further in NG+. Perhaps Huntsman's copse will be nice.