Mana Echoes and Mycosynth Lattice on the battlefield.
You control at least three Soldiers.
({4} magic symbol) available.
Steps
Cast Recruit the Worthy with buyback by paying ({4} magic symbol) , creating a 1/1 Soldier creature token and returning Recruit the Worthy to your hand.
When the Soldier enters the battlefield, Mana Echoes triggers, adding ({1} magic symbol) for each Soldier you control.