({6} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) at most available.
Steps
Cast
Nature's Rhythm from your hand by paying ({6} magic symbol) ({G} magic symbol) ({G} magic symbol) or from your graveyard for its harmonize cost by paying at most ({6} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) , searching your library for
Metamorphosis Fanatic and putting it onto the battlefield.
When
Metamorphosis Fanatic enters, it and
Preston trigger.
Resolve the
Metamorphosis Fanatic trigger, returning an applicable target from your graveyard to the battlefield.
Holding priority, activate
Altar of Dementia by sacrificing
Metamorphosis Fanatic.
Resolve the
Preston trigger, creating a token copy of
Metamorphosis Fanatic that is a 0/1 Illusion.
When the
Metamorphosis Fanatic token enters, it triggers, returning
Metamorphosis Fanatic from your graveyard to the battlefield.
Repeat from step 2.
Results
Infinite ETB.
Infinite LTB.
Infinite creature tokens.
Infinite death triggers.
Infinite mill.
Infinite recursion of creature cards in your graveyard.