For X and two Black mana, you get a sorcery that makes each opponent lose X life, and you then gain life equal to the amount lost because of the card
For just three mana and sacrificing an artifact, Tinker lets you tutor any artifact in your deck directly onto the battlefield, which allows for things like a Turn 1 Blightsteel Colossus or God-Pharaoh's Statue or Bolas's Citadel, all of which are pretty close to unbeatable
Three counterspells, and suddenly you are actively digging toward whatever win condition your deck is built around, all while efficiently stopping your opponents dead in their tracks
The artwork on the cards is gorgeous, making them appealing to collectors, and the foil treatment is noticeable but not overpowering
Double Raise Dead is an exceptionally powerful and underrated card