Max observed how the three people faced Akuji. He decided to use his third eye because he didn’t want to waste much time figuring out their identities.
With the third eye, Max could see their soul flames. Physical identities in the human world often do not match their soul flames.
Physical traits are sometimes like a mask that covers the true personality. There are people who appear good, but their soul is stained with blood.
The kindness they display is merely a disguise to achieve their goals by exploiting others. There are also human bodies that are just a disguise, a hiding place for phantom, a type of demon that can camouflage itself as a human to live in the human world.
Phantom can cross from their world to the human world through rituals and sacrifices. The human body that is sacrificed becomes a vessel for the spirit to live in the human world.