in SOD...
Spoilerripped off his cracked skin right after he became a lich. There is nothing to suggest that all liches have to do that. Perhaps Xykon simply lacked the spell Gentle Repose and didn't want to rot.
I don't think V has been out of his cabin enough to know if he has an aura of fear that affects exclusively low-level characters that look at him and do not happen to be immune, such as paladins.