Enlightened

Human sages are those humans that have spent a very long time training their abilities and honing their skills.

Specific requirements for attaining Sagehood have not been detailed, but they seem to involve living for a very long time and having specific qualities (similar to how demons need to have specific qualities to have the demon lord's seed).

Human sages also have very strong wills and thus are much more difficult for demons to manipulate or to crush their hearts.

Many of the strongest warriors have risen to the rank of Human Sage.

They also seem to retain the strength comparable to Arch Demon and incredible longevity of humans.

Personality
Human sages typically are less prone to emotional swings and tend to have a keen intellect. Their vast battle experience and calm minds allow them to be deadly on the battlefield and very good at analyzing situations off of the battlefield.

Abilities
Human sages are known to have very high battle abilities, but the actual skills they wield will vary greatly.

They seem to be able to take advantage of the abilities of God Class Armor and Weapons.

The Seven Celestial Sage

 * Rudra's Royal Knight No.3 to 10
 * Gadra
 * Adalman
 * Azu
 * Dana
 * Vena
 * Gerald
 * Gran

The Ten Great Saints

 * Hinata Sakaguchi*

Holy Knight Order

 * Reynald Jesta
 * Arno Bauman
 * Bacchus
 * Ritase
 * Gerald
 * Fritz

Three Martial Saints

 * Sare
 * Grigori
 * Glenda
 * Even though Hinata is mentioned as one of the Ten Great Saints, who are all sages, it is unknown if she is a Human Sage. It's also implied she may be a Human Saint.

Человек Мудрец