Kamen Rider Den-O Episode 49

By the time the DenLiner returns to the present, Kai uses his energy to destroy the city and links the present to his time. Ryotaro and Momotaros arrive at a building Kai is on, at which Ryotaro tells Momotaros his wish to fight alongside him to the very end. While Momotaros, along with Yuto and Deneb, fight off the Imagin army, Den-O confronts Kai and the Death Imagin. Kai unleashes his timepulse surge, turning the entire area into ruins, at which point Ryutaros arrives to try to save Ryotaro.