Activate Zimone and Dina by tapping it and sacrificing Bloodghast, causing you to reveal cards from the top of your library until you reveal a land card, put that card into your hand, and then put that card onto the battlefield, and draw a card and put up to one land from your hand onto the battlefield if you control eight or more lands.
When the land(s) enter the battlefield, Bloodghast and Retreat to Coralhelm trigger that many times.
Resolve all Bloodghast triggers, returning it from your graveyard to the battlefield.
Resolve all Retreat to Coralhelm triggers, untapping Zimone and Dina.
Repeat.
Results
Near-infinite landfall triggers.
Put all lands from your hand and library onto the battlefield.