The previous deck was more low to the ground with a lot of aggressive, recursive threats. Unfortunately, this format doesn't facilitate low-curve aggressive decks. Instead, the early threats were quickly outclassed by mid-game threats and synergies.

The new reanimator deck is more midrangey. It has big top end threats but the goal isn't necessarily to turbo out a Grave Titan on turn 3. Every deck has creatures and when they die, they will want to get them back. Reanimate is rarely going to be a dead card, even when it isn't reviving a game ending threat.

Egon, God of Death is the commander but the real leader is the back side, Throne of Death. It follows the philosophy that the command zone should enable the synergy but not determine the win condition. Throne of the Dead can start filling your graveyard from turn 2, powering up your reanimator spells.