Preston, the Vanisher | Phyrexian Altar | Nature's Rhythm

(and one other card)

({4} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) at most available.

Cast
Nature's Rhythm by paying at most ({4} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) , searching your library for
Faceless Butcher and putting it onto the battlefield.
When
Faceless Butcher enters, it and
Preston trigger.
Resolve the
Faceless Butcher trigger, exiling another creature if needed.
Resolve the
Preston trigger, creating a token copy of
Faceless Butcher that is a 0/1 Illusion.
When the
Faceless Butcher token enters, it triggers, exiling the nontoken
Faceless Butcher.
Activate
Phyrexian Altar by sacrificing the
Faceless Butcher token.
When the
Faceless Butcher token dies, it triggers, returning
Faceless Butcher from exile to the battlefield.
Repeat from step 2.

You can either cast
Nature's Rhythm from your hand or for the harmonize cost, adjusting mana requirements accordingly.