Havi, the All-Father | Sakashima the Impostor | Phyrexian Altar

Cards

Activate
Phyrexian Altar by sacrificing
Sakashima the Impostor, adding one mana of any color.
When
Sakashima the Impostor dies, it and
Havi trigger.
Resolve the
Havi trigger, returning
Sakashima the Impostor from your graveyard to the battlefield as a copy of
Havi.
Resolve the
Sakashima the Impostor trigger, returning any legendary creature card with mana value 5 or less from your graveyard to the battlefield.
Repeat.

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