How do I change the in game character image

[yhminus2]

Hi guys

I want to change the in game shield image, not in inventory image, equipped with character.
For example unique monarch decorated with eagle

So What kind of image file do I change?
each character Weapon 2 Hand image or else?

and I think if I change the Weapon 2 hand image, all of monarch shield (normal, magic, rare, unique) are shown like monarch with eagle right?
Is there any other way to distinguish these situation?

Normal, magic, rare monarch - seem to be equipped with original monarch image
unique monarch - seem to be equipped with monarch with eagle image