Zinnia, Valley's Voice | Hullbreaker Horror

Cards

You control up to five lands that can tap to produce at least ({4} magic symbol) ({U} magic symbol) .
You control a nonland permanent that can be cast using at most three mana that lands you control can produce.

Activate up to five lands by tapping them, adding at least ({4} magic symbol) ({U} magic symbol) .
Cast
Peregrine Drake by paying ({4} magic symbol) ({U} magic symbol) plus an additional ({2} magic symbol) for its offspring cost.
Hullbreaker Horror triggers, returning another nonland permanent from the battlefield to your hand.
When
Peregrine Drake enters the battlefield, it triggers twice.
Resolve the first
Peregrine Drake trigger, untapping up to five lands.
Holding priority, activate up to five lands by tapping them, adding at least ({4} magic symbol) ({U} magic symbol) .
Resolve the second
Peregrine Drake trigger, creating a token copy of it that is 1/1.
When the
Peregrine Drake token enters the battlefield, it triggers, causing you to untap up to five lands.
Activate up to five lands by tapping them, adding at least ({4} magic symbol) ({U} magic symbol) .
Cast the nonland permanent returned to your hand in step 3 by paying its mana cost.
Hullbreaker Horror triggers, returning
Peregrine Drake from the battlefield to your hand.
Repeat from step 2.

This combo has been estimated to be Exhibition (Bracket 1+).