Originally Posted by WhattayaBrian
I don't believe this is true, and, if it is, it's a bug.
I am not quite sure where I have obtained this information and did not believe it myself first but I think I've read it on two different sites as well as been told by a friend that such is the case with the Q's of both Syndra and Karthus.
Karthus I can understand if it's true since his Q acts differently depending on if it hits one or multiple targets but since Syndras' Q has no such interaction I found it curious, I will attempt to find where I've read it and link it.
Oh yeah here we go, firstly I saw someone write it as a comment on Syndra on leagueoflegends.wikia.com which I thought nothing of since he had no proof of it, but after a friend of mine told me it's true I started thinking and then when I read the post below I figured "Hey, I guess it's true."
Though he has edited the part about her Q by crossing it over.
Also I went into a custom game to check it out and, on minions at least, Muramana does not give any bonus damage to her Q.
Apologies for providing incorrect information.
So I assume that it did in fact to apply it earlier due to a bug which later got fixed.