Trained only to fight, they mostly know no other way of living or of getting what they want save by force. It is shown in the anime how they were raised very differently from humans, and even as they escaped the Khilbet lab where they were experimented on, they were still very indifferent to normal human interactions, such as Irene being surprised by Kai helping her in Paris. This indifference is due to the fact that they were only trained to do what was necessary for them to survive, particularly fighting and feeding on human blood, and that being taught to live within society was never the goal of their creation.
Apart from the fact that the Schiff's only goal is survival, the individuals composing them has a tendency to lean towards each other. They are shown to be very cooperative and often talk before planning to do something, such as the debate over whether they should seek help from Saya and Haji when Van Argiano hunts down the Schiff with the Corpse Corps. This willingness to do everything together can be traced from the very lab they were experimented on, since they needed each other to survive when they were given chiropterans to kill, and when they escaped the lab together in search of hope that the humans around them talked about. Since their experience at Khilbet the Schiff have developed feelings of disdain towards most humans and believe the only people they can trust are each other.
Like chevaliers and chiropterans, the Schiff have enhanced speed and strength, and must drink blood to survive. However, they are different in two key ways: sunlight will burn them to death, and they form a condition they call "Thorn" that causes them to slowly crystallize. It initially manifests itself as red cracks that usually appear on the neck, spreading along the body until the afflicted Schiff shatters completely.
The Schiff also seem to have the capability to wander around during day time, though they must wear cloaks to protect themselves from the sun. This is shown when Irene freely wanders around Paris, but gets weakened when the sun starts coming out.
Slaves at first, the ten Schiff decided they wanted to be free and escaped from the lab where they were created, killing most of the Cinq Flèches scientists there.
Due to the parting words of one the scientists from the lab, the Schiff were led to believe that they were created from Saya's blood, which is why they initially attempt to kill her before learning the truth. They attack Saya and Haji, but when one of the Schiff, Ghee, drinks Haji's blood, it kills him almost instantly. When Irene is afflicted with the Thorn, Saya offers her blood to her, believing that it could save her. However, this only causes the Thorn to spread faster and kills Irene, making the other Schiff suspicious of Saya's intentions. They then realize that the scientist lied and that it is Diva's blood they require to live, not Saya's, and devote themselves to hunting Diva down. Due to Karman and Moses' reluctance to accept help from Saya, they are eventually wiped out by the Corpse Corps, with the only remaining member being Lulu, who escapes and joins Red Shield.