Twilight's Fall – a separate game. Twilight Imperium's expansions, mods and rules topics are not part of it.

Indoctrination

At the start of a ground combat: You may spend 2 influence to replace 1 of your opponent's participating infantry with 1 infantry from your reinforcements.
Yin Brotherhood originAbility – Biotic

Biotic

At the start of a ground combat:

You may spend 2 influence to replace 1 of your opponent's participating infantry with 1 infantry from your reinforcements.

1in the deck
–chance to draw

Source: Twilight's Fall