A Crimson Lord (紅世の王, Guze no Ou), also simply called "Lord" (王, Ou), is an existence, amongst the Crimson Denizens, possessing great power. Because of their large existence, they require a lot of Power of Existence to continue to manifest themselves in our world. They also have the power to move between worlds freely. But in the war to protect balance of worlds, those who have Flame Haze and protects both worlds are called "Lords" , while Denizens are entitled to those who consume existence to live.
The main difference between Lords and Denizens is the former's superior abilities to possess Power of Existence and utilize it. Even though normal Denizens can take possession of a great amount of Power of Existence, they can't master them as well and they still won't be considered Lords. There are also some Denizens who were born with qualification to become Lords, but haven't demonstrated their full strength yet, so they are still considered by others to be only "Denizens".
Among the Lords, there are some who exceed other Lords; they are usually addressed as the powerful Lord (強大なる“紅世の王” Kyōdai-naru Guze no Ō ).
Also, the Crimson Gods, who are embodiment of Crimson Realm's very laws themselves, are simply viewed by some only as powerful Lords, despite their supreme power as Gods.
Normal Denizens who make contract to human for the mission to protect the balance are honorably named as Lords even if they aren't actually Lord-class Denizens. For the Lords who work to maintain the balance, they take care of the balance of the world by monitoring the Power of Existence and utilizing their Flame Haze to terminate those Crimson Denizens who harm the balance. These Lords represent themselves as magical objects called Divine Vessels, which in Shana's case is a pendant. They can manifest fully, but to do so requires tremendous amounts of Power of Existence and in turn, would be detrimental to the balance of the world. Examples of Crimson Lords are members of Bal Masqué such as Sydonay, Dantalion, Bel Peol, Hecate and Sabrac.
- Author Yashichiro Takahashi compares the difference between Crimson Lords and normal Denizens to that of a "warship" and a "motorboat"; if you apply the amount of gasoline warships use into motorboats, they won't become faster and would even sink into the sea because of the weight of that fuel.