[quote=@OneStoryToMany]
Not just their magic.  They could steal skills,  languages,  knowledge,  experience,  blah blah blah. Depending on the symbology used (for instance the eyes could be symbolically linked to a person's perspective ) you could steal whatever is symbolized.  However,  once an individual does that in their brain it's linked like that. So they'd permanently think (eyes = perspective) in this case.  So they don't always target a person's magic necessarily. 
[/quote]

That makes sense. Maybe consider adding this to their description?