This is a little odd - it's a permanent, which means it can easily be destroyed or stolen (if it's not already protected by EA/PA), and also acts as an Elite Armagio except in a different slot - the only probably is, it could very well be the same thing as Bone Wall, but instead of absorbing the # of hits (useful against a non-massive amount of creatures), it absorbs damage (which only affects low attacking guys).
It has potential use, but I don't like the idea as much as I wanted. Maybe it could
heal you for the amount of HP you consume from a creature? This is too much like an automated Gravity pull with no restrictions on who it can eat on your side (couple it with a Quintessence-affected Brown Nymph giving HP to everything on your side, and you might as well be immortal).
Not to mention - momentum will still bypass this thing, correct? They stealing it from an opponent that uses
specifically won't be very helpful, considering they'd still have mobs and skills to bypass the shield already...