In D&D, metallic dragons (bronze, copper, brass) are in opposition to chromatic dragons (red, blue, green, etc.), chromatic being the typical evil, sometimes cruel and selfish dragons while the metallic dragons are mostly altruistic and righteous creatures
You can preorder the set now from your local game store, online retailers like Amazon, and elsewhere Magic products are sold.
The Golden Lure Module is a different story, though
This is part of a cycle, and all the Praetors have their own versions
New guests are always welcome
Whats more, the ability to do a little bit of damage to planeswalkers really helps and can stack with cards like Frost Bite to deal with them relatively mana efficiently