Casting spells with K'rrik, Son of Yawgmoth, tutoring with Spoils of the Vault, drawing cards with Necropotence, all these together can put us in a position where we've run out of life to spend before we found a way to win the game
The mana value of the spell is determined by only its mana cost, no matter what the total cost to cast that spell was
Its also very mean with extra combat steps, which angels like Aurelia, the Warleader provide
Legends' Legacy Dihada, Binder of Wills and Shanid, Sleepers' Scourge are traditional foil cards
Nothing says trouble like a reedy hiss with a hint of liquid gurgle
Or maybe even if he could produce mana of any colour to enable things like Cranial Plating