It is most useful when your opponent has already built up a field full of monsters (5 monsters in the regular game, 3 monsters in Duel Links), and they're ready to beat your life points (LP) down to zero, or close to zero, that turn
Playing cards that need to pay LP is the strategy of the Deck, while gaining as little advantage as possible
Ideally, you want to have a card like Crucible of Worlds [] or Life From the Loam [] as a back-up safety net in case this plan falls through, but neither card is necessary for the strategy to work
Eldritch Evolution and Neoform often act as simple tutors that help assemble combos or transmute your commander into something threatening
I'll let you know, I will protect myself from whatever you have planned. Feldon's Cane is an ultra-cheap artifact that lets you shuffle away your graveyard at any time, and the ultimate card in this category