Each hero power costs two mana and can be activated once per turn
The first is essentially to protect an essential Sorcery or Instant from discard, for example, Urza Outcome can play one, as Josh McClain did, to find Paradoxical Outcome if the opponent takes it with Thoughtseize
Diabolic Intent I still see Diabolic Intent as a relatively underplayed and underrated tutor
With prowess creatures or (then legal) Vivi Ornitier on the board, his mana generation let you churn through cantrips and create some huge threats - and when your opponent removed him, you could fireball them in the face
Orzhov is overflowing with excellent reanimation spells: Unburial Rites, Dread Return, and Exhume are classics, and The Cauldron of Eternity and Debtors Knell will allow you to reanimate creatures repeatedly over multiple turns
Without further ado, lets get this ceremony underway