Master of Berserker of Black during the Great Holy Grail War, Caules is the eldest son of the Forvedge family who was born as a spare successor for the family and as a caretaker to his older sister.

As his sister became the head of the family and approached the highest seat of Yggdmillennia under Darnic after many months, he began to explore other avenues for his life rather than live as a piddling magus who would never accomplish anything. The Holy Grail War interrupted those plans, and while he was originally to travel to Romania as simple backup, the Command Spells began to manifest upon his arrival. With no choice, he was forced to participate as a Master.

(Source: Type Moon Wiki)