Fate/Zero - Season 2
Sinopsis
“War for the Holy Grail - Pursuing the power of the "Holy Grail" which grants a miracle, this is a contest in which seven mages summon seven Heroic Spirits to compete for it. In the battle whose conclusion was postponed three times, now, the fourth war commences. Amongst the mages, there was a man who was always alone, and could not find out the meaning behind his life. His name was Kirei Kotomine. Not comprehending the guidance of fate, Kirei was lost, and had kept questioning why someone like him was given the Command Seals. However, a nemesis crossed Kirei's path. That person is - Kiritsugu Emiya. A merciless mage killer and assassin-for-hire who sought the miracle of the Holy Grail on behalf of his wife's family - the Einzberns. Merely recited in fragments in Fate/stay night, this is the Fourth Holy Grail War that took place 10 years prior. The truth that unfolded behind the battle between Shirou's foster father, Rin's father, and the younger Kirei Kotomine, is finally revealed.”