Interrogate Them - Exile the top three cards of target opponent's library
If you want to go the best storytelling route, combine the Hand, Eye, and Book of Darkness to create the actual Vecna, an 8/8 indestructible Zombie God that gets the triggered abilities of all three
These cards are meant to provide that little bit of extra oomph, not support an entire tribal deck on their own
I would expect to see Grief out of decks such as Jund, Deaths Shadow variants, Orzhov Taxes, and possibly even black-based combo or Reanimator decks
Pioneer vs
For instance, an aggressive deck typically features numerous 1-drops and 2-drop cards, resulting in a ladder-like curve