The goal of this deck is to hit with Maelstrom Archangel, and then draw/cast your entire library. And sideboard.
The big win: Swing with Maelstrom Archangel, and then cast Gifts Ungiven before the angel hits. You need to get four cards that will win you the game on the spot. First card is Coalition Victory: you simply win. The next card is Emrakul, the Aeons Torn: you will very likely win. Your opponent can't give you these two cards. So what other cards do you want? I choose Omniscience and a second Gifts Ungiven. The Angel hits, you resolve Omniscience and cast Gifts Ungiven again. Thanks to Emrakul, she, Coalition Victory and Gifts Ungiven are back in your library! Repeat the process, but instead of getting Omniscience, let's get... well, whatever you want.
So this deck is playing cards in 5 colors, and is playing the most expensive cards possible. What else goes in? Bring to Light becomes a tutor for any 5 CMC instant, sorcery or creature. So it can fetch the Maelstrom Archangel, or any card you need given the board state. Need life? Chromanticore. Opponent has too many creatures? Fumigate. You're out of gas and need more cards? Day's Undoing. You have Emrakul in your hand and wish you could cast her? Jodah, Archmage Eternal. You really, absolutely need to fetch a card that Bring to Light won't allow? Fetch Glittering Wish, and get Detention Sphere, or Merciless Eviction, or Cruel Ultimatum, or Nicol Bolas, Planeswalker.
Maelstrom Archangel and Jodah, Archmage Eternal are good ways to play your crazy expensive cards. Why not throw in a single Fist of Suns too? At least this isn't a creature that can die. And now you can cast those stupid cards in your deck that you happened to draw at the wrong time. Might as well add a few more stupid expensive cards then! Like how about Time Stretch, for when you need a few more turns before you win. Or Enter the Infinite, in case you're not great at top decking.
Now for the boring part. Manabase needs to be consistent and needs to trigger Coalition Victory, so one-of each fetch land and each shock land brings us to 20 cards, and then add in four more basic lands to get to 24. Throw in Sakura-Tribe Elder to chump a creature and fetch a basic, and throw in Firespout and Radiant Flames to keep the board clear while you build your economy.
This deck is fun because you don't need more than a single copy of most cards, which means you have a huge variety. This also means Gifts Ungiven and Bring to Light make for great times. Your opponent will have a hard time choosing which gifts not to give you, because they will all be amazing gifts.
The sideboard needs some work (maybe include some more utility cards, like Maelstrom Pulse), and certain main deck cards could be changed, like Day's Undoing.
