Many energy cards are primarily designed to be one or the other, and exploiting the differing rates of returns between them using the efficient generators to fuel the powerful outlets is a big part of deckbuilding around this mechanic
Those in turn are based on largely Germanic fairy tales told to children, sanitized for a more puritanical American audience
Tortured Existence trades creatures between hand and graveyard, Frantic Search loots and untaps lands so you can keep mana up, and Reanimate just grabs the real thing when needed
You can do this at instant speed, letting you sneak some damage through your opponents who might not be paying attention to your open mana, and very likely, not to the abilities you have tacked on those lands
A player may have two commanders if each of them has the partner keyword, with the two partners together combining their color identities for the deck
When the time for upgrades does come, there are a variety of products to choose from that will provide you with new cards, either through additional play experiences or through the unique thrill of unwrapping brand new booster packs
