Hellbent - If you have no cards in hand, instead search your library for a card, put it into your hand, then shuffle your library
Polluted DeltaPolluted Delta, Watery GraveWatery Grave, Morphic PoolMorphic Pool, and Shipwreck MarshShipwreck Marsh will help make sure you always have access to as much blue and black mana as you could ever need
Modest advantages like this are the stars of competitive gameplay
Creature - Human Soldier Ally
It also massively improves your first combat by giving your creatures first strike and untapping them, which allows for much safer and potent aggressive plays
The thinking is that, by adding Eldrazi Displacer to the creature mix, I decrease the burden of actual creature removal, which frees me to play Thought-Knot Seer over Dromokas Command, which helps against control and ramp decks