Boros Garrison from your hand onto the battlefield, and then repeat this process once if you control eight or more lands, putting any other land from your hand onto the battlefield instead.
When
Boros Garrison enters the battlefield, it,
Bloodghast and
Retreat to Coralhelm trigger.
Resolve the
Boros Garrison trigger, returning it from the battlefield to your hand.
Resolve the
Bloodghast trigger, returning it from your graveyard to the battlefield.
Resolve the
Retreat to Coralhelm trigger, untapping
Zimone and Dina.
Repeat.
Results
Infinite card draw.
Near-infinite ETB.
Infinite draw triggers.
Near-infinite landfall triggers.
Near-infinite LTB.
Near-infinite death triggers.
Near-infinite sacrifice triggers.
Put all lands from your hand and library onto the battlefield.