Activate Prava of the Steel Legion by paying {W} due to Agatha of the Vile Cauldron, creating a 1/1 Soldier creature token.
Activate Phyrexian Altar by sacrificing the Soldier, adding {W}.
Repeat.

Infinite death triggers

Infinite creature ETB

Infinite creature LTB

Infinite creature sacrifice triggers

Prava of the Steel Legion

Agatha of the Vile Cauldron

Phyrexian Altar

Tap Kydele for {6}.
Pay {2} to Stonework Packbeast to add {W}.
Pay {3}{W} to Prava to create a 1/1 Soldier token.
Pay {1} and tap the Soldier token to untap Kydele with Aura of Dominion.
Repeat.

Infinite creature tokens

Kydele, Chosen of Kruphix

Aura of Dominion

Stonework Packbeast

Tap Kydele for {6}.
Pay {2} to Signpost Scarecrow to add {W}.
Pay {3}{W} to Prava to create a 1/1 Soldier token.
Pay {1} and tap the Soldier token to untap Kydele with Aura of Dominion.
Repeat.

Signpost Scarecrow

Tap Kydele for {6}.
Pay {2} to Gemstone Array to put a charge counter on Gemstone Array.
Remove the counter to add {W}.
Pay {3}{W} to Prava to create a 1/1 Soldier token.
Pay {1} and tap the Soldier token to untap Kydele with Aura of Dominion.
Repeat.

Gemstone Array

Tap Kydele for {6}.
Pay {2} to Prismite to add {W}.
Pay {3}{W} to Prava to create a 1/1 Soldier token.
Pay {1} and tap the Soldier token to untap Kydele with Aura of Dominion.
Repeat.

Combos with "Prava of the Steel Legion"