some suggested changes, to take certain elements into account...

On it being heavy. Very true. This also means its not too quick to change direction after it builds up momentum. However, it can still lash out with its clawed limbs. 

The hardness of its scales also means that most things that would penetrate armor simply push it about.

Oh, and on the conditioning... Not even the Order of Idris can fully control it. its more point and release than something that is guided. The reclamation is done through a certain food only found in the dominion.
The creature is fairly simple-minded. Intricate plans go beyond its grasp. Its mind is also about as dense as its hide. i.e. Its persistent. When it gets an idea into its head, it'll keep going at it long beyond what one would expect.

on the climbing: the structures that can take its weight tend to be hard for it to grab onto, thus its essentially out of the question to climb. But it can jump.