Balan, Wandering Knight can single-handedly push your opponents into despair if equipped with Lightning Greaves and Behemoth Sledge early, which both have low mana costs
Card advantage is generally preferable to ramp effects
Each pack contains one foil card of random rarity, two rare or better cards, three uncommon cards, and six common cards
Individual bending abilities like Waterbend, Earthbend, Firebend, and Airbend can work outside the set, sure but Avatar Aang himself becomes much harder to build around effectively, especially if your goal is flipping him consistently
Culling the Weak Weve looked at a few cards that sacrifice creatures to generate mana, but Culling the Weak does it the best because it turns a creature of any size into 4 mana