Greavers are broken. No, not in the sense that they are a challenging, difficult enemy. The sense that from behind a wall, they have ghost-range on their mist cloud that inflicts their status. Not only that, the status mist can inflict status on you from behind the wall. I vaguely remember other enemies being able to damage through walls, but I'm certain Greavers have much more misleading range.
In addition, the status mist is incredibly difficult to see, and can hit you from further away than the actual graphic, even when taking latency into account. Greavers can behave exactly the way they do now, but their status mist is just broken.
Really, Greavers would be no problem to fight at all if it wasn't for the mist. I haven't seen the status get inflicted to anyone behind walls yet but I would definitely agree that the mist needs to be a lot more noticeable. I love a challenging fight, but can't stand an unfair one.
Fighting Greavers that can inflict stun or shock is horrible. In tight spaces it's a tragedy all because I can't see a stupid cloud.