This magnificent spell-copying symphony scales exponentially thanks to Riku of Two Reflections, whose second ability piggybacks on creature entries while his first handles your spells. When you drop Astral Dragon onto the battlefield, its Project Image trigger zeroes in on a noncreature permanent to duplicate—which, in this case, is masterfully multiplied by Primal Vigor's replacement effect to flood the board with dragon copies of that permanent. Riku of Two Reflections then lets you pay {G}{U} to clone Astral Dragon itself, which Primal Vigor immediately doubles into an absurd horde of thirty-two new dragons. Those new Astral Dragon tokens immediately trigger *themselves* upon arrival, setting off a compounding cascade that creates near-infinite creature tokens and near-infinite creature ETB triggers.