MTG Salvation

I'm going to make an argument for Temple Bell here. If your goal is to end the game before it goes on for too long, you don't want to be spending 2 mana a turn drawing cards; that's too expensive. Yes, Temple Bell gives your opponents cards, but if you're killing them quickly, this doesn't matter so much as your opponents are only getting an advantage if they can actually find the time to play the cards you've given them. Yes, sometimes this means giving your opponents useful cards, but I think the upsides seriously outweigh the downsides here. And remember, just because an opponent is drawing a card doesn't mean that card is going to be directed towards you. Cards you give opponents that they use to thwart your other opponents directly helps you. That's like pouring gasoline on a fire.

Fateful Showdown is a lot harder to evaluate since it really depends on a lot of different things. How often your hand stays topped off, how often you want to wheel, etc...