This loop relies on Rofellos, Llanowar Emissary tapping to churn out massive amounts of green mana based on your Forests, which easily covers the cost to replay it while leaving plenty of profit behind. To get around summoning sickness the moment it hits the battlefield, Shang-Chi, Master of Kung Fu grants all your creatures the ability to activate their abilities as though they had haste, while also chipping in restricted mana just in case. Finally, Temur Sabertooth provides the escape hatch by bouncing Rofellos back to your hand for a modest fee, letting you recast the elf over and over to continuously harvest green mana and stack up endless enters-the-battlefield triggers.