So this deck really has three phases.
Phase 1: just playing the game, waiting to start your engine.
Phase 2: You transformed Liliana by sacrificing a creature on the turn she was played. Trying to reach her - 8 emblem
Phase 3: Once you've got your emblem, you play some more of the big creatures, aiming to win via board state. Your sacrifices become free effects and board wipes mean nothing to you.

To help this strategy, you need to protect and accelerate Liliana. Darkness is an exceptional card here, for 1 mana you can prevent all combat damage done to your planeswalkers. In addition, you have a wide selection of bombs that should take the attention off of your win condition, as well as multiple ways of bringing it back without having to pay commander tax. The constant discarding and sacrificing opponents will have to do will also limit the amount of options they have to target your win condition with, so when you bring it back, it'll be more likely to succeed.