Why aren't Lucian and Vayne friends?
I always wondered why is it that the two most similar champs not friends?
and 
are both Demacian monster hunting ADCs whom have lost their loved ones to the things they now hunt, Vayne hunts presumably evil mages, and Lucian hunts the undead, which overlaps with the mages seeing as how undead are created from foul dark magic, and many are evil mages themselves.
Despite this they have no interaction with each other both lore wise and in game.
EDIT: The only slight interraction they have is they share a skin line; heartseeker.
