Activate Altar of Dementia by sacrificing Twilight Shepherd.
When Twilight Shepherd dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to Giada.
Resolve the Altar of Dementia ability.
Repeat.

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite mill

Infinite sacrifice triggers

Infinite self-mill

Giada, Font of Hope

Twilight Shepherd

Altar of Dementia

Activate Ashnod's Altar by sacrificing Twilight Shepherd.
When Twilight Shepherd dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Activate Ashnod's Altar by sacrificing Twilight Shepherd.
When Twilight Shepherd dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
Repeat.

Infinite colorless mana

Mikaeus, the Unhallowed

Ashnod's Altar

Activate Ashnod's Altar by sacrificing Twilight Shepherd.
When Twilight Shepherd dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to Vizier of Remedies.
Repeat.

Vizier of Remedies

Activate Viscera Seer by sacrificing Twilight Shepherd.
When Twilight Shepherd dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Thran Vigil triggers, putting a +1/+1 counter on Twilight Shepherd.
Resolve the Viscera Seer ability.
Repeat.

Infinite scry 1

Viscera Seer

Thran Vigil

Activate Ashnod's Altar by sacrificing Twilight Shepherd, adding {C}{C}.
Twilight Shepherd dies, triggering its persist ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Twilight Shepherd enters the battlefield, triggering Denry Klin, putting a +1/+1 counter on Twilight Shepherd.
Repeat.

Denry Klin, Editor in Chief

Sacrifice Twilight Shepherd to Phyrexian Altar to add {R}.
Twilight Shepherd's persist triggers, returning it to the battlefield with a -1/-1 counter.
Sacrifice Twilight Shepherd to Phyrexian Altar to add {1}.
Twilight Shepherd triggers, returning it from your graveyard to your hand.
Pay {R} to Sneak Attack to put Twilight Shepherd onto the battlefield from your hand.
Repeat.

Infinite colored mana

Phyrexian Altar

Sneak Attack

Sacrifice Twilight Shepherd to Thermopod to add {R}.
Twilight Shepherd's persist triggers, returning it to the battlefield with a -1/-1 counter.
Sacrifice Twilight Shepherd to Thermopod to add {R}.
Twilight Shepherd triggers, returning it from your graveyard to your hand.
Pay {R} to Sneak Attack to put Twilight Shepherd onto the battlefield from your hand.
Repeat.

Combos with "Twilight Shepherd"