Probably ideas for Limited/OP Races, Spells, and Items.
Here's what I got:

Dragoons only three can be in the roleplay at the same time (20) <-- Population
Half man half dragon, more powerful than Draconics and take a more human like appearance.

Dragoon Spirits: Created by Eight Powerful Elemental Elder Dragons:

Fire, Water, Earth, Air, Lightning, Ice, Darkness, Light. And then there is the Omni-Dragoon which is made by combining all gems together.

Boundary Manipulation: Limited to one person or NPC only, this character can not engage in combat unless provoked. This power may not be used to create paradoxes such as the user is vulnerable to attack while using Boundary Manip, but doing so to prevent even THAT!

[Url=powerlisting.wikia.com/wiki/Boundary_Manipulation] Boundary Manipulation[/url]

Also after matarials are created how does this sound: anything that is within four tiers of the tier of armor and weapon you currently have can break the armor. Anything not within four tiers will not damage the armor. (Note, the exception to this rule is Enchanted Dragon Steel, which needs Normal Dragon Steel to ATTEMPT to break it.