The human heart was considered to be something of great strength. How strange, then, that they were able to consume it so completely and totally. The heart was warm, wet and moist. Sky knew from his parent's memories that hearts were made of muscle, fats, and other bodily material. He couldn't think. Instinct took over, and it was feral, primal. Sometime, in a primordial world before buildings and fire and humanity, dragon's still reigned the skies unthreatened and unparalleled. 

"Sleipnir, where do we go now? I'm... I'm very tired." He told his brother, earnestly. The heart and the dead body before him became cold. The walls and ceiling were cold to the touch and because he had no shoes or socks he felt the cold greatly. 
-
Halley gazed on as the dragon's and hydra alike freed themselves from their bonds. The ygdrassil, the tree at the center of the world, had within it dew and miraculous nectar that bestowed the dragon's with their famed strength. Now, the keeper dragon's blood was a small grain of sand to the universe of the ygdrassil, but it was more than most dragons were able to touch in their entire lives. 

"Let's get going, eh? Anyone have a plan?"