After installing the Saber Class Card, for a certain reason, maybe because he is male, Zachary obtained a set of armor very similar to Saber's from Fate/Prototype and Fate/Prototype: Fragments of Sky Silver, showcasing the fact that the Saber Class Card from the Fifth Holy Grail War may invoke the Heroic Spirit King Arthur in general rather than just one version even though Excalibur stays the same.
After being placed into a Doll body, while fighting, he starts rampaging while ignoring injuries.
Fate/kaleid liner PRISMA☆ILLYA 3rei!!Edit
He is first mentioned by Kirei Kotomine when he was explaining the Ainsworth Holy Grail War history to Shirou. He then appears as one of the dolls, used by Julian Ainsworth, to fight against Shirou Emiya. He is his sixth opponent during the Ainsworth Holy Grail War. They start a battle in a cemetery, clashing with their sword until Shirou cuts his left arm making him unleash Invisible Air in order to use Excalibur, ignoring the loss of his arm and pushing Shirou back for a moment. He proceeds to use his Noble Phantasm with only one arm, which makes his right arm break since the sword wasn't meant to be swung with a single hand, before being shot by Shirou's Broken Phantasm.
After this, he was still standing. Shirou prepares himself to fight him until one of them breaks but Zachary's helmet falls off and he says to Shirou that he will leave Julian to him before finally leaving the Doll's body where he was put into. As Kirei arrives on the scene, he reveals that Zachary was Julian's father and then prays for his "pitiful" soul to rest in peace.