PSY is not in the Illuminati.
PSY is an independent agent who released Gangnam Style in an attempt to prevent I Kissed a Girl from taking over the world after the inevitable wane in Justin Bieber's influence. He began this process before Katy Perry began her World Domination meta-plot. That is called a pre-emptive strike. Despite this, he has failed before the unimaginable power of Perry.
PSY was memorialized by Carlos Santana in his hit song "Smooth".
PSY based his campaign on the ancient Chinese principles of warfare. He tossed out a brick to get a jade gem, crossed the sea without the emperor's knowledge, and waited at leisure while the enemy labored. However, he made a major blunder in forgetting to retreat, which lost him not only the campaign, which was doomed anyway, but also the larger war.