First, to the cards:
Summoner's Pact
0
Sorcery - Green
Search your library for a creature and put it into your hand.
Shuffle your library.
At the beginning of your next upkeep, pay 2

or lose the game.
Western Tolaria
Land
Transmute 1UU
Western Tolaria comes into play tapped

: Add

to your mana pool
Now, it may just be me jumping to conclusions, but both of these cards seem extremely good in this format. In any deck with Spirit Guides, which remain eminently playable in combo, Summoner's Pact adds a storm and a mana, while not requiring one to use up any actual mana from their lands. This card will definitely be played in Belcher; it's too good not to be. Guides have not been run in Long lists recently, but this may make them good. Tolaria, on the other hand, is just absurd. It gets Black Lotus or Academy, at instant speed, and is uncounterable. I just can't add to that.