The lists for almost all of the Paradoxical Outcome decks run this
1 Snapcaster Mage
1 Gitaxian Probe
1 Merchant Scroll
1 Ponder
1 Time Walk
1 Tinker
1 Treasure Cruise
1 Ancestral Recall
1 Brainstorm
1 Dig Through Time
4 Force of Will
4 Paradoxical Outcome
4 Preordain
I tried a Mono Blue package when I was preparing for SCG Con and I found that I needed more I win cards so I added White for Monastery Mentor and some removal spells. Looking at the current variants out there some people play Black for tutor and draw or Tendrils and some play Karn.
My question is why isn't this deck just Blue? There is Karn, Scion of Uzra and Sai, Master Thopterist as additional I win cards and Thoughtcast adds more card draw. Then, you have the underplayed Transmute Artifact and several bounce spells.
The reason for a mono colored deck is to reduce the impact of disruption and increase the efficiency of the deck. Some will say that without the tutors and removal the deck cannot fight back and Pyroblast is just going to wreck you. I would add Hydroblast and play some of the blue removal spells. The ability to play Timetwister also gives the deck a booster after a stack battle you can reload and win. I know Brainfreeze is also underplayed but as a one of it can beat the Jeskai decks if you sequence it correctly.
Work in Progress
4 Paradoxical Outcome
4 Force of Will
3 Preordain
2 Karn, Scion of Urza
2 Sai, Master Thoperist
2 Voltaic Key
2 Sensei's Divining Top
1 Blightsteel Colossus
1 Erayo, Soratami Ascendant
1 Snapcaster Mage
1 Echoing Truth
1 Hurkyl's Recall
1 Tinker
1 Ponder
1 Dig Through Time
1 Brainstorm
1 Brain Freeze
1 Treasure Cruise
1 Merchant Scroll
1 Gush
1 Ancestal Recall
1 Time Walk
1 Timetwister
1 Time Vault
2 Mox Opal
1 Mana Crypt
1 Sol Ring
1 Mox Pearl
1 Mox Ruby
1 Mox Emerald
1 Mox Sapphire
1 Mox Jet
1 Black Lotus
1 Mana Crypt
6 Island
2 Misty Rainforest
2 Scalding Tarn
1 Flooded Strand
1 Library of Alexandria
1 Tolerain Academy
Sideboard
3 Hurkyl's Recall
3 Tormod's Crypt
3 Grafdigger's Cage
2 Flusterstorm
2 Reality Shift
1 Hydroblast
1 Island