Activate Ashnod's Altar by sacrificing Gravebane Zombie, adding {C}{C}.
Gravebone Zombie is put on top of your library instead of into your graveyard.
Cast Gravebane Zombie from the top of your library by paying {0}.
Repeat.

Infinite colorless mana

Infinite creature ETB

Infinite creature LTB

Infinite creature sacrifice triggers

Infinite storm count

Gravebane Zombie

Rooftop Storm

Ashnod's Altar

Future Sight

Activate Altar of Dementia by sacrificing Gravebane Zombie.
Gravebone Zombie is put on top of your library instead of into your graveyard.
Resolve the Altar of Dementia ability, causing target opponent to mill cards equal to Gravebane Zombie's power.
Cast Gravebane Zombie from the top of your library by paying {0}.
Repeat.

Infinite mill

Altar of Dementia

Activate Phyrexian Altar by sacrificing Gravebane Zombie, adding one mana of any color.
Gravebone Zombie is put on top of your library instead of into your graveyard.
Cast Gravebane Zombie from the top of your library by paying {0}.
Repeat.

Combos with "Gravebane Zombie"