From what we've discussed, I'd say that we're likly dealing with a medium-small to lower end large in terms of size. Also the dragons are highly intelligent based off of larger brain, and that we're controlling them as our avatars. The dragons will likly be mortal but as reptiles of this size will probably have ridiculously large life spans from young 1-100 yrs or elders of close to a 1000yrs. The human lore doesn't call us daemons or such but humans hunt us for title and glory.
In the appearance department wyverns, western and winged eastern dragons are acceptable. You may use most any appearances from bones plates scales or the such. One to two sets of wings is advised, and no basalisk, hyrdas or other dragonoids. There is no dragon born magic or very little due to species wide extinction event of over hunting. Breath weapons are allowed in classic dragon types: fire, water, wind, poison, acid, ice and maybe thunder. No sub elements like energy, plasma or metal.