Lets share some interesting rulling...
http://www.mtgcast.com/?p=3704Lets say your opponent is at -10 and you are at 1 and you have a persecutor.
Your opponent attacks you with a 6/6 and a 1/1 and you block with the persecutor which is assigned lethal damage.
What happens? Interesting enough you lose. Here’s why. When damage has finished being dealt, we check state based actions.
When we check them, we see that there is lethal damage on the persecutor and you are at 0 life.
So the game simultaneously puts the persecutor into the graveyard and makes you lose the game.
Death’s shadow has a static ability that alters its power and toughness by giving it -X-X where X is your life total.
Now it seems straight forward, but what happens id your life total is at -10?
If you are at -10, we insert it into the X and we get Death’s Shadow gets -(-10),-(-10).
So we then distribute the negative into the parentheses and get +10,+10.
So your Death’s Shadow would be a 23,23.