Cast Graf Reaver by paying {0}.
When Graf Reaver enters the battlefield, it triggers, causing you to sacrifice it.
When Graf Reaver dies, Enduring Renewal triggers, returning it to your hand from your graveyard.
Repeat.

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Infinite storm count

Rooftop Storm

Enduring Renewal

Graf Reaver

Cast Graf Reaver either from your hand or from the top of your library by paying {0}.
When Graf Reaver enters the battlefield, its exploit ability triggers, causing you to sacrifice it.
When Graf Reaver dies, Mortuary triggers, putting it on top of your library from your graveyard.
Repeat.

Mortuary

Realmwalker

Combos with "Graf Reaver"