You can discard and draw to trigger its synergies
One of Magic's best black enchantments and best black ETB cards, it offers strong value thats easy to understand and build around, and it even works well in generic decks that lack a reanimation or graveyard focus
On its own, Bloodthirster can dome each opponent for six damage each turn
It's a mana sink, and if your dork brings mana with it, like Priest of Gix, then you can make infinite blinks and then many more combos too
Being able to flip a 15/15 Worldspine Wurm up is a great party trick, but there are other great cards in here like Ashaya, Soul of the Wild, and Aesi, Tyrant of Gyre Strait
It generally doesn't matter what you hit assuming you have no total duds to hit like counterspells in your deck, you will get a good deal of what you want because your deck will be doing a thing