If Karou could drive, her license would need to be printed on one of those lenticular cards. You know, those fun cards that, when you tilt them left, there's one picture on them, but when you tilt them right, there's a different picture? From one angle, our protagonist is Karou—the blue-haired artist. From the other, she's Madrigal—a chimaera executed for having an affair with Akiva, a seraphim. Together, she's... well, she's a hot mess in the middle of an identity crisis. When most people try to find themselves, they don't actually find another person inside of them. Karou does.
Questions About Identity
Why did Brimstone hide Karou's true identity from her?
Now that Karou has discovered that she is Madrigal resurrected, should she live her life as Madrigal would? Are Karou's seventeen years as herself now null and void?
When chimaera resurrect, they sometimes go into a new body. How does this affect their identities (how they perceive themselves and how others perceive them)?
Chew on This
Even though they're basically the same person, Karou and Madrigal must be different because they were raised in completely different worlds.
Brimstone didn't just make a new body for Madrigal to enter after her execution. He made her a brand new identity: new name, new body, new life.