Demons

Demons are creatures of no definite shape that emit an essence called miasma. They are almost completely subject to the will of their human contractor.

Abilities
Demons are capable of eating human beings and other animals. They are able to take a human host, at the cost of the contractor (host) being devoured of their soul and rendered lifeless. Demons can shapeshift into various creatures, a notable practitioner of this being Yulli. They can also hide their presence.

Weaknesses
Demons are vulnerable to the light and can perish from light magius. This was the reason why Deor was locked up in the castle until recently; to keep him from exposure to the harsh light and Luxafixa spells near the border that can affect his constitution. Additionally, demons tend to be cowards, often breaking their contract and fleeing if an opponent is too powerful.