Gideon's Phalanx

Create four 2/2 white Knight creature tokens with vigilance.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, creatures you control gain indestructible until end of turn.

Magic Origins

Put four 2/2 white Knight creature tokens with vigilance onto the battlefield.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, creatures you control gain indestructible until end of turn.

Magic Origins Promos

Check to see if there are two or more instant and/or sorcery cards in your graveyard as the spell resolves to determine whether the spell mastery ability applies. The spell itself won’t count because it’s still on the stack as you make this check.

If the spell mastery ability applies, the four Knight tokens will also gain indestructible until end of turn.