User blog comment:Dream Mist the Dragon Trainer/NEED ANSER IF IT EXISTS/@comment-24398536-20160919073719

In the game the Legendary dragons category tab in the Hangar is for the servants of the Legendary dragons so to speak.

Meaning Brute, Seedling, Primal and Exiled dragons.

On the pages of the actual Legendary it says that you cannot put them in the Hangar. They are more like buildings in the game, like Johann's ship, a nothing else.