MTG Salvation

This is pretty good as just a much more efficient Jalum Tome. It's almost a trap though, since you typically want to loot away lands, and this tricks you into looting away actual gas. Still, you can just fireball someone out old-school style with the mana this thing can generate on the flipside.

so, this + Eternal Scourge and/or Misthollow Griffin seems cool

Could be a fun standard combo engine piece. E.g., stall board for a little while, then Torment of Hailfire for a bajillion. I wonder if the opp destroys Azor's Gateway, and you play another, if that other one sees the previously exiled cards or not. If memory serves, if it's like Ashiok, it doesn't.