I certain agree with basing the prediction on the mobs health. If you're running for example guards at Sultan but not cycling Sultan, the # of predictions that have succeeded shouldn't matter. If you hit the guards 5 times, then the Sultan ignores your skill and smacks you on #6, that's certainly not cool.
If you're using prediction to cycle the Sultan though, after he gets wounded he should be trying harder to kill you. If he's injured, he should ignore prediction entirely.
Just my thoughts.