5 Armagios/titans and momentum for the armagios + this=win. And those cards have enough survivability that they could be on field without trouble.
On second note, this doesnt vary from catapult enough to be useful. Catapul=Sacrifice+Damage based on HP. This does the same thing, just to more monsters. Does this effect opponent too? Would be OP mass kill for no damage if you combod with Dim shield.
I'd say a no on this one, nice idea, but to overpowered and redundant.