What I like about this deck is that it's aggressive and can end the game quickly, but also has resilience and staying power.

I went with Pit Fight over Mutant's Prey so I can reliably use it on my undying creatures. Given the relative lack of other instants, Prey Upon might be better than either until rotation.

I also moved rancor to the sideboard because I found the deck worked better playing the midrange/tempo side more often than not. This also further reduces the hit the deck will take post rotation. Currently thinking Young Wolf --> Elvish Mystic; Strangleroot Geist --> Kalonian Tusker.