It served as both combo enabler and wincon, especially in conjunction with Agatha's Soul Cauldron, which could transfer its mana-making ability to other creatures
How Decide Between Two Copies and One Copy Lets start with the easy cases
Perhaps one Commander thats a bit off the beaten path that allows Hildibrand Manderville to show his true potential is Ratadrabik of Urborg
Reanimation is a famous and quite powerful black archetype with cards like Entomb, Griselbrand, and Animate Dead
Replacing the 5-cost Artifact Door to Nothingness - one of our all time favorite, ridiculous cards in the seldom seen 'all five' MTG color combo - is the perilous The Bridge of Death
A deck like Syr Gwyn, Hero of Ashvale or Greven, Predator Captain loves this