Activate Warren Soultrader by paying 1 life and sacrificing a creature, creating a Treasure token.
When the Treasure enters, Haliya triggers, causing you to gain 1 life.
Activate Stimulus Package by sacrificing the Treasure, creating a 1/1 Citizen creature token.
When the Citizen enters the battlefield, Haliya triggers, causing you to gain 1 life.
Repeat.
This clever loop turns the raw materials of Stimulus Package—which starts you off with two Treasures and lets you cash them in for 1/1 green and white Citizen creature tokens—into an engine of perpetual motion. Warren Soultrader provides the dark alchemy needed to feed those Citizens right back into the machine, sacrificing them and paying a single life to forge brand-new Treasures. Meanwhile, Haliya, Guided by Light acts as your perpetual motion stabilizer, translating every new artifact and creature entering the battlefield into a steady stream of life to offset the Soultrader's cost.