You get to draw cards, and with one of the best colorless ETB effects in the game you get protection from everything, which buys you time to actually put your cards to good use
These are the most rare cards in the game, and therefore highly sought after
This means your opponent has time to come up with a defense for anything you play
Artifact lands work, and theyre free to play because theyre lands, so you can ramp up affinity with them
A lot of people are upset with this card because of the set it came out in, The Big Score
Stuff like Snuff Out or Dismember are already heavily played cards, but here, you get to draw a card from them because you lost 4 life, and you also get to drain your opponents for 2 life, offsetting your life loss