You control a Plains or have a Plains in your graveyard.
Steps
Activate
Thaumatog by sacrificing a land.
Repeat step 1 until you control no lands.
Activate
Viscera Seer by sacrificing
World Shaper.
When
World Shaper dies, it triggers, return all lands from your graveyard to the battlefield tapped.
When the lands enter,
Emeria Shepherd triggers that many times.
Resolve an
Emeria Shepherd trigger that was triggered by a Plains, returning
World Shaper from your graveyard to the battlefield.
Resolve all remaining
Emeria Shepherd triggers.
Resolve the
Viscera Seer ability.
Repeat.
Notes
You can return all nonland permanents in your graveyard and library to the battlefield if you control there are two or more Plains between your graveyard, library and battlefield. To do this, have all triggers from
Emeria Shepherd target desired permanents. Then, resolve the Plains triggers first to return those cards to the battlefield, causing all other triggers to fizzle on the stack.
Results
Infinite LTB.
Infinite ETB.
Infinite sacrifice triggers.
Infinite death triggers.
Infinite scry 1.
Infinite self-mill.
Infinite landfall triggers.
Return all nonland permanents from your graveyard to the battlefield.