It looks good so far, the mana curve doesn't look as big but it's still manageable. The number one thing you HAVE to do for this deck is this: PROTECT
CHAMPION OF RHONAS. It will win you so many games simply because it's ability will let you play big creatures from your hand for free. When it attacks, exert and give it flying, when it's about to be dealt damage,
flash in
vizier of deferment and remove it from the board, if it's targeted for a spell use
hapatra's mark and give it hexproof. the
champion of rhonas will be your secret weapon to your deck because even if you do have 8 or 9 mana on the board you can use that towards instant and sorcery spells rather than just flopping a creature and hoping the enemy doesn't counter it.