Zacama, Primal Calamity | Elesh Norn, Mother of Machines | Shivan Wurm

Cards

Lands you control can tap to produce at least ({4} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) .

({2} magic symbol) plus enough mana to pay for commander tax, if applicable available.

Activate all mana-producing lands you control by tapping them, adding at least ({4} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) .
Cast
Zacama either from your hand or from the command zone by paying ({6} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) plus commander tax, if applicable.
When
Zacama enters the battlefield, it triggers twice.
Resolve the first trigger, untapping all lands you control.
Activate all mana-producing lands you control by tapping them, adding at least ({4} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) .
Resolve the second
Zacama trigger, untapping all lands you control.
Cast
Shivan Wurm by paying ({3} magic symbol) ({R} magic symbol) ({G} magic symbol) .
When
Shivan Wurm enters the battlefield, it triggers twice, returning itself and
Zacama from the battlefield to your hand.
Repeat.
If lands you control can tap to produce at least ({5} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) , this combo nets infinite mana, and you may use that mana to activate
Zacama's other abilities.