Each one of them was a reformed being, having been domesticated by the masters one by one.
There were several that were responsible for the deaths of hundreds of mortals over time, and smaller elemental beasts that primarily infected areas with disease and disruptions.
Dragons can be the cause of landslides and bridges failing; they can equally corrupt a mind or feed an ulcer, inflame and fever, suppurate and contaminate.
However, the monks motto “tame the dragon and you will release Humanity” was a maxim they lived by. If ever any of the creatures reverted to their old ways, they would thrash them with a switch, or beat them with their brooms.
The dragons were compelled to stay within the confines of the cloister because the monks were empowered to hold them. And this deep magic had begun and continued with the help of the elvish adept, Puck.
It had started with salamanders, and continued on with beasts the size of trees, who bore the breath of a crematorium.
-Gabriel Brunsdon, Finding Self - Second Guesses- Azlander Series






