Havi, the All-Father | Sakashima of a Thousand Faces | Altar of Dementia

Cards

All permanents on the battlefield (
Sakashima of a Thousand Faces as a copy of
Havi).

Activate
Altar of Dementia by sacrificing
Sakashima of a Thousand Faces.
When
Sakashima of a Thousand Faces dies, it and
Havi trigger.
Resolve the
Havi trigger, returning
Sakashima of a Thousand Faces from your graveyard to the battlefield as a copy of
Havi.
Resolve the
Sakashima of a Thousand Faces trigger, returning any legendary creature card with mana value 5 or less from your graveyard to the battlefield.
Resolve the
Altar of Dementia ability, causing target player to mill cards equal to
Sakashima of a Thousand Faces's power.
Repeat.

Infinite LTB.
Infinite ETB.
Infinite sacrifice triggers.
Infinite death triggers.
Infinite mill.
Infinite self-mill.
Put all legendary creature cards with mana value 5 or less from your graveyard onto the battlefield.