Vision's Foe has Eyeloss as secondary effect. If you want to give a unit the eyeloss ability, The Master of the Shadow Blossom is the best one to use since he's not unique (none of the hero units are, but they can only appear once per nation unless multihero) and his only other tag was demon, iirc.
It's #eyeloss or something. No need to copystats. But it's a defensive thing. I'm going to remove it from the unit and add a seconday effect to the tongue attack instead.