I wasn't finding it on my dictionary =X
Actually, I found bestow on the dictionary, but the only meaning there was "outorgar". I didn't know what that meant =P Now I know that "outorgar" is "give".
put simply bestow means give, so if you have a hero with vamp aura and he has mirror image and you have that enabled the mirror images will have vamp aura and they will give it to others units.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.