Knights was Mathilde's ability to manifest an army of heterogeneous troops made of crimson flames within her range of perception, allowing her to combat a large number of opponents. It was an extremely powerful army due to the fact that the troops, which were composed of knights and beasts, could each fight independently and were each as strong as an average Flame Haze. In Eternal Song, Knights were only portrayed as humanoid armored knights. Knights could also be produced to look exactly like Mathilde. She could also manifest them in the form of the two attacks Hajōtsuchi and Vorpal Phalanx, and could convert the troops into flames and explode them.
Mathilde could also use this Unrestricted Spell to manifest other things, such as the large swords and halberds she wielded in battle, a line of spears, only the bows and arrows and arms of archer troops, and a steed which she could use to fly. In Eternal Song, she could also fly by manifesting what looked like wings made of flames. She often materialized her weapons and horse by calling for them, but she can do so without calling.
According to Eternal Song, there were four types of Knights:
- Heavy Type (重装型 Jūsōgata ): Heavily armed infantry units used for close combat and as a defensive wall to protect Mathilde. They wield halberds (斧槍 onoyari ) as primary weapons.
- Regular Type (通常型 Tsūjōgata ): Commonly used, these armed units can ride horses and wield many types of weapons: halberds, maces, swords (剣 tsurugi ), spears (槍 yari ), shields (楯 tate ) and bows (弓 yumi ). Sometimes they wield a large battering ram called Hajōtsuchi (破城槌, lit. "Castle-breaking Hammer") to break through fortified gates. They are also used to perform the Vorpal Phalanx (
大殲滅 密集突撃Daisenmetsu Misshūtotsugeki (Vōparu Farankusu) , lit. "Grand Massacre - Close Assault"), one of Mathilde's most powerful attacks; it strengthens her individual attack by utilizing lance-wielding Knights to pierce the area where the attack would occur, allowing her to cleave through stronger opponents.
- Light Type (軽量型 Keiryōgata ): A lighter version of the Regular Type, they are used for battles in small areas or inside buildings. They wield swords and shields as primary arms.
- Long-range Type (遠距離型 Enkyorigata ): Light-armed units used for long-range attacks. They wield bows and arrows as primary weapons. The projectiles they shoot also create explosions when they hit targets. Mathilde once used them to destroy most of Merihim's Rinne, Aeria.
In modern times, Wilhelmina Carmel had accused "Commander of Thousand Conquests" Orgon's Unrestricted Spell Legion of being a cheap imitation of Knights. However, Legion used Orgon's essence and was his existence itself, whereas Knights was a manifestation of Mathilde's visualization of strength. Orgon wasn't imitating Knights and it was extremely difficult to copy someone else's inherent Unrestricted Spell, so Wilhelmina's statement was a false accusation.