Complex sentence: He unleashes the power of the Ryūmyaku, which is seen to have been sealed by Minato's hirashin kunai, causing a light to envelop Naruto and Yamato, whom was trying to stop Naruto.
Split into simpler sentences: He unleashes the power of the Ryūmyaku, which is seen to have been sealed by Minato's hirashin kunai. Causing a light to envelop Naruto and Yamato, whom was trying to stop Naruto.