Soul Ransom
 
That converted mana cost and those first two lines of game text set a very high bar, one that almost no cards can ever reach. Soul Ransom lacks the sheer deck-destroying, game-swinging power of its famous ancestors, but it makes up for it by being just a lot more interesting to play with and play against. When you cast it, your opponent has an out, sometimes an immediate one or one that can happen mid-combat - but one that also plays into what was likely your deck's strategy anyway, and one that adds up in your favor in the battle of attrition and card advantage that the Dimir play so well.
 
Constructed: 3/5
Casual: 3/5
Limited: 3/5
Multiplayer: 3/5
EDH/Commander: 3/5