Obviously a WIP. I really think this is a strong base. Sylvan Caryatid is a bit sweeper-weak, so the win cons are mostly planeswalkers which avoid that. Thassa is mostly an engine here, but acts as a way to double the speed of your Aetherling clock. Depends what else is in Theros, but I can see Aetherling being replaced, as well as the general removal/draw suite. The deck essentially cycles through to its win conditions via scry and a lot of defense; obviously, if you already have your win cons, scry essentially becomes a way to keep you from being mana flooded.
4 Sylvan Caryatid
4 Omenspeaker
1 Ætherling
4 Magma Jet
3 Izzet Charm
2 Mizzium Mortars
2 Turn//Burn
2 Syncopate
2 Cyclonic Rift
1 Counterflux
1 Lightning Strike
1 Urban Evolution
1 Thassa, God of the Sea
4 Xenogos the Reveler
2 Jace, Architect of Thought
1 Jace, Memory Adept
1 Ral Zarek
4 Stomping Grounds
4 Breeding Pool
4 Steam Vents
4 Temple of Abandon
4 Temple of Mystery
4 other lands i cant even be bothered with
4 Sylvan Caryatid
4 Omenspeaker
1 Ætherling
4 Magma Jet
3 Izzet Charm
2 Mizzium Mortars
2 Turn//Burn
2 Syncopate
2 Cyclonic Rift
1 Counterflux
1 Lightning Strike
1 Urban Evolution
1 Thassa, God of the Sea
4 Xenogos the Reveler
2 Jace, Architect of Thought
1 Jace, Memory Adept
1 Ral Zarek
4 Stomping Grounds
4 Breeding Pool
4 Steam Vents
4 Temple of Abandon
4 Temple of Mystery
4 other lands i cant even be bothered with