Wow, that deck is nasty.
Wouldn't wanna play a Red or Black deck against that.
But before you have a lock on, you're pretty vulnerable.
Have you considered more defensive parts? Propaganda
? Pendrell Mists
Or card draw in Rhystic Study
or Phyrexian Arena
All of these options require mana to stop them, maybe you could also pop in Ankh of mishra
It would work well with Bloodchief Ascension, getting it active quite quickly.
Other effects like Static Orb
or Winter Orb
would make these effects a soft lock for a few turns, and force your opponents to play lands if they wanted to actually play anything.
A lot of your cards really nerf creature cards, putting them into the graveyard from the top of the deck , or at upkeep next turn. Vengeful Pharaoh
It seems like a better choice than No Mercy, as it's a lot less vulnerable than No mercy to a sweeper. (back to nature, cough cough)
Plus, if your life is getting low, you could actually play it on the field.
If you have some extra draw on the field, this sucker's downside (no draw) wouldn't be so bad.