Lilia Vanrouge

Lilia Vanrouge is a third-year in Diasomnia and Malleus' supervisor. He is a mysterious person who, although having the appearance of a young boy, is rumored to be an ancient being. He likes to surprise and mess around with people. He raised and adopted Silver. According to Silver, Lilia served the lord of the Valley of Thorns and was a former soldier who repeatedly threw himself to the flames of the war, and has earned medals for it.

(Source: Twisted Wonderland Wiki)