Isaac Foster

Japanese Name アイザック・フォスター
Romaji Name Isaac Foster
Nicknames Zack
Series Satsuriku no Tenshi
Age 20
Weight N/A
Height 186 cm (6’1″)
Date of Birth July 24
Blood Type B


Isaac Foster, also known as Zack, is a complex character with a unique personality in the anime series “Satsuriku no Tenshi” (Angels of Death). Zack often speaks in foul language and doesn’t hesitate to curse, even at the young protagonist Rachel Gardner. He lacks formal education and struggles with reading and understanding complex explanations. However, he possesses a high level of instinctive and survival intelligence and relies on his instincts to navigate through difficult situations. Zack is brutally honest and despises lies, always speaking his mind without embellishment.


Zack’s troubled past contributes to his dark and twisted personality. He grew up in a run-down orphanage where children were abused and left to die. His caretakers were abusive, calling him a monster and forcing him to bury the body of a deceased child. One day, while watching a horror movie about a serial killer, Zack became fascinated and inspired by the killer. He began mutilating and murdering his caretakers and burying them in the orphanage’s backyard. As the years passed, his notoriety as a serial killer grew, making him a wanted criminal.


Zack’s appearance contributes to his menacing aura. He is a tall man, estimated to be in his 20s, with a height of 6’1″. He has black hair and black eyes on his right side, while his left eye has a distinctive gold color. Zack is often seen wearing a brown hoodie with red pants, creating a distinctive and recognizable look.


Despite his lack of formal education, Zack possesses formidable physical abilities. He is exceptionally strong and agile, with incredible speed and strength. These physical attributes allow him to overpower his opponents and navigate through dangerous situations. Zack’s lack of academic intelligence is compensated for by his high instinctive intelligence, allowing him to rely on his instincts to survive and make quick decisions.


Zack’s character originates from the anime and manga series “Satsuriku no Tenshi” (Angels of Death) created by Makoto Sanada. He serves as the deuteragonist of the series, initially appearing as an enemy of Rachel Gardner, the protagonist, before becoming an ally. The series follows their journey through a mysterious and deadly building known as the “Tower of God”, where they must navigate through various floors filled with traps, puzzles, and dangerous individuals.


The provided information is based on the character profile from and the anime series “Satsuriku no Tenshi”.

Isaac Foster – FAQ

Who is Isaac Foster?

Isaac Foster, also known as Zack, is one of the main characters in the anime and video game series “Satsuriku no Tenshi”, also known as “Angels of Death”. He is a serial killer who meets the protagonist, Rachel Gardner, in a mysterious building.

What is Isaac Foster’s personality like?

Isaac Foster is portrayed as a complex character with a dark and twisted personality. He displays a violent and unstable nature, often taking pleasure in killing. However, he also shows moments of vulnerability and genuine concern for Rachel, forming a complicated relationship with her throughout the series.

What is Isaac Foster’s backstory?

Isaac Foster’s backstory is slowly revealed throughout the series. He grew up in an abusive and neglectful environment, which contributed to his violent tendencies. As a child, he experienced trauma and developed a distorted view of the world that led him to become a serial killer.

What are Isaac Foster’s motives?

Isaac Foster’s primary motivation is to find joy and meaning in life through killing. He believes that by ending the lives of others, he can experience a sense of fulfillment. However, as the story progresses, his motivations become more complex, intertwining with his relationship with Rachel and his desire for self-discovery.

Does Isaac Foster have any redeeming qualities?

Despite his violent nature, Isaac Foster shows some redeeming qualities throughout the series. He shows moments of vulnerability, empathy, and even self-sacrifice for Rachel’s sake. These instances suggest that there may be more to his character than a cold-blooded killer.

What is the nature of Isaac Foster’s relationship with Rachel?

Isaac Foster’s relationship with Rachel Gardner is a central aspect of the story. At first he intends to kill her like his other victims, but they develop a unique bond as they overcome the challenges of the building they’re trapped in. Their relationship evolves into a complex mix of trust, dependence, and understanding, blurring the lines between friendship and something deeper.

Is there any character development for Isaac Foster?

Yes, Isaac Foster undergoes significant character development throughout the series. As he spends more time with Rachel and faces more challenges, he begins to question his own motives and perceptions. This introspection leads to moments of self-reflection and personal growth that ultimately shape his character and actions as the story progresses.