Dark Dragon Rising

Dark Dragon Rising is the 423 season episode In The Manny Centurions The Clash of Kaijudo

Trivia

 * Valka revealed that Manny And Hiccup are Step-Brothers
 * Valka revealed that was the Wife of the Dragon Master
 * Manny found out that his father has two wives
 * Yu did never has Step-Grandmother in her half of the family