FRIEND is a dark parallel to the SOUL and it controls Dess from inside like we do with Kris.
Notice how every time the Knight roars and opens its ribcage, you can see an eye in there? An eye with a long vertical pupil. Like a CAT'S EYE.

Hey doesn't that eye in the Knight's chest look like a cat's eye?

>>713370785
The Knight also notably has an eye inside its torso when it roars