Once you internalize that, the card evaluations below become obvious: ask of every card, is this a source or a payoff, and does the rest of my deck cover the other side? Best lifegain sources (the engines) You want repeatable, incremental gain lots of small triggers beat one big lifegain spell, because payoffs like Vito or Archangel of Thune care about the number of times you gain, not just the total
They all tap for one color, but if you put two colors into them and sacrifice them, you get a pretty decent ability
Mass Board Destruction (except Upheaval) Cards like Worldfire and Sway of the Stars don't deserve to be on the banned list
Bone Saw | Illustration by Kev Walker These are artifact spells that cost mana to cast
19 | Copy that card
Otherwise, be prepared to face Thoughtseize every time you play against a black deck, be it against midrange decks like Jund, Deaths Shadow, Rakdos, Dredge, or combo decks like Yawgmoth or Esper Reanimate