Zirnitra is actually child #2, 3 and 4 because it's a three headed dragon with a body for each head - the left is Theo (generally unimpressed, the 'logical' head and dedicated to Asmodeus), the middle is Hallelujah (more commonly called Holly, the independent, aloof character) and the right is Harmony (he needs to cut down on the sugar)
More info can be found in their profiles, if anyone wants to plot anything, hit me up here or there