Summoner's Pact

you don't need to pay the cost if it is part of the game winning combo ;)

The thing is that you have to cast this at the end of your opponent's turn. That way you can be certain he hasn't got the mana to bounce or destroy your mana producing permanents. Sure, it might slow you down a bit but that's always the better alternative to outright losing the game. Remember, this card makes killer combos.

only use this, if you know with out a doubt your gonna win in the next turn, and not have to pay the cost. i think its too much unless you have a platinum angel out, that is protected, like with a diplomatic immunity. there is poentental with this, just be careful. ive lost using this card, because my opponent used a bounce spell on the end of my turn, returned a forest, and then he did it on his turn too. didnt have the mana to contunue. it was a great game though, taught me alot.
lots of luck