This deck works in 1 way: Gain momentum. Gain counters. Swing hard, fast, and early. Loses to early removal. Beats most long games. Constantly makes someone have to come up with answers. Failure to do so, even in turns 1-3, means that the momentum it gains can't be stopped, except by a field wipe.
In short, hit them hard. Once.
This deck is for people who like to have a ton of creatures out on the field, like to build a crapton of mana, like 20/20 creatures, or all of the above.
Advice to make this better is appreciated. Rundown of how I'd play:
The dream:
Turn 1-2:
I got 3 Burning-Trees, a land, a shrine, Caller, and Elvish Mystic! Play the land and Mystic. Turn 2, play the 3 burning trees and shrine. Use shrine for Caller. Get 1-5 cards free!
Turn 3+
You just got +1-5 on your opponent, the ability to gen double digit mana, drop something huge for free, and do whatever you want. Oh. And you can get another 1-5 cards. You've won. Just hit them hard.
Good draw:
Turn 1-2
So, you got a burning tree, Elvish, Shrine, and a land. First turn, land and Elvish. 2nd, Burning-Tree. If you have another Elvish, play it now. Else, just drop a 2 cost Sylv or Voyaging. If they kill something, it'll slow you down, but hey. You've got a lot going already.
Turn 3
Start building that devotion base. Drop what you can. Play to whatever the opponents are doing.
Turn 4
Ready to explode? You should be. If you can gen 9 mana in a turn by this point, you should be able to start controlling the game. This is the point when you know you'll win or lose.
Bad/Horrid to come. Don't have much time to finish this before I have to leave work/sleep.
Essentially, you need to be able to gen mana/turn rations as follows. If you can, you're in good shape. Most of the time, you can.
Turn/Mana range
1/1
2/2-3
3/4-6
4/6-10
5/9-14
6/13-20