A commander of the Eldian Unit of the Marley army. Formerly one of the chief overseers of the first Warrior candidates during their training, he later led the Eldian Warriors in the Marley Mid-East War against the Mid-East Allied Forces, playing a key role in Marley's victory.

Spoiler

Through the support of Willy Tybur and the governmental party of Marley, along with the death of General Calvi, Magath is next in line to become the general of the Marleyan military forces.

Spoiler

He sacrifices himself by blowing up the Marleyan ship to prevent the Yeagerists from catching the allies

(Source: Attack on Titan Wiki)