Imagine if T10 can turn back-and-forth to Dragon using "Flame of Krogdalo" or something. You can get the "Ember" via various contents or by weekly quest.
Myth Dine=Dragon of Water/Ice, Myth Pega=Dragon of Wind/Blizards, Myth Doom=Dragon of Hell/Fire, Myth Voltarion=Dragon of Thunder/Lightning.
And "Crystal or Tears of Krogdalo" can turn back to T10 Horses via buying at specific NPC.