Ramp like Sol Ring, Arcane Signet, Boros Signet, and the Mardu Talismans make sure you always have the mana to drop threats fast and recover after board wipes
Hogaak, Arisen Necropolis and Uro, Titan of Nature's Wrath are prime examples of cards that enabled such powerful graveyard strategies it took the ban hammer to keep them buried
Doubling Season is a great example of this
Theres a small amount of token creature generation and trigger copying present as well, but not enough to focus on as your game plan
Of course, you'll want to replay Sephiroth to do it all again for a second, third, fourth, fifth, or sixth emblem and make every death hurt as much as possible