Valiant Veteran

Other Soldiers you control get +1/+1.
{3}{W}{W}, Exile Valiant Veteran from your graveyard: Put a +1/+1 counter on each Soldier you control.

Magic Online Promos

"Let them come. We will show them that Argivian steel is stronger than any Phyrexian metal."

Dominaria United

Dominaria United Promos

Exiling Valiant Veteran from your graveyard is part of the cost to activate its last ability. This means that once it has been activated it is no longer in the graveyard, and players can’t respond to it by removing it from your graveyard to prevent you from activating it.