"Gabriel" or "The Holy Spirit" is the main antagonist of The Mandela Catalogue and the first Alternate[1]. He served as the overarching antagonist in Act 1, and the main antagonist in Act 2. It is a Type Two Alternate first appearing in Overthrone, where it systematically sabotages the Annunciation, and presumably prevents Christ from being born. After this, it claims itself to be the "one true savior" of humanity, implying that it has taken Christ's role in history.

This so-called Gabriel is a pale-skinned, blond-haired archangel seen wearing white robes. When showing his true appearance his eyes grow in size and his mouth is stretched into a smile. This alternate has some slight differences from true Archangel Gabriel, such as a longer face and hair and a lack of wings.

"Gabriel" often speaks in a whisper. He claims to be the one true savior of humanity, whether genuinely believing it or mocking the idea is unknown. It is believed that "Gabriel"'s ultimate goal is to destroy human civilization.

The True Gabriel is seen at the start of Overthrone delivering the message of Christ's birth to the shepherds before departing with a choir of angels. It is implied that true Gabriel was replaced with a false one after this.

The Alternate Gabriel's first appearance is during his message to Mary. He is first seen with an impossibly stretched, alien-like face before being censored by a black box. He tells her that he has a message, and when Mary responds surprised the screen goes static and whispering can be heard. With close captions on, the following can read in binary: "I am the one true savior. I must reverse the delusion. Joseph is next." to which Mary supposedly complies.

"Gabriel" later appears in Joseph's window as he sleeps, telling him: "I will fool the shepherds. I will know their greatest fear. I will know your greatest fear." then repeatedly telling Joseph to wake up.