User blog comment:IE2555/A discovery on the Official Website.../@comment-24197955-20140214150023/@comment-24538292-20140215153152

It makes little sense because they do both have a similiar goal.

Lucian's "some call it magic, I call it good aim" is clearly just a joke about himself. He doesn't disbelieve in actual magic. Even his guns are imbued with magic.

I think the cause of theis may be simply because Lucian was created a lot earlier than Vayne, and so they don't "know" eachother in the same fashion as Kha'Zix doesn't know Malzahar.