Quote from Hoplito FavoritoWay too much fat. You don't need 4x Keranos, you don't need Medomai at all and you could probably cut a Ral Zarek. I'd try something like this for permanents:
1 AEtherling 2 Keranos, God of Storms 1 Ral Zarek 2 Jace, Architect of Thought
Also your spell base should be more focused. Boros Charm is a dead card for a Control deck, you don't have enough burn for it actually kill them and the other modes do nothing. Lightning Strike has a mostly irrelevant upside (you aren't a true burn deck) compared to something like Izzet Charm. I do like Warleader's Helix though.
I'd probably do something like this (if I wanted to keep the 8 sweeper style):
DeckMagic OnlineOCTGN2ApprenticeBuy These Cards
Creatures (3)2 Keranos, God of Storms1 ÆtherlingEnchantments (4)4 Detention SphereInstants (14)2 Quicken4 Izzet Charm4 Dissolve4 Sphinx's RevelationSorceries (10)2 Mizzium Mortars4 Anger of the Gods4 Supreme VerdictPlaneswalkers (3)2 Jace, Architect of Thought1 Ral ZarekLands (26)4 Hallowed Fountain4 Sacred Foundry4 Steam Vents4 Temple of Enlightenment4 Temple of Epiphany4 Temple of Triumph1 Island1 Plains
You have lots of ways to reclaim lost tempo with sweepers, which helps to alleviate the greedy, 12 tapland mana base.