[{quoted}](name=Sukii Nightshade,realm=NA,application-id=3ErqAdtq,discussion-id=cwci7oRG,comment-id=0000,timestamp=2015-02-04T03:49:37.187+0000)
Well it doesn't do damage. It only marks and allows you true damage for basic attacks for 6 or 8 seconds (can't remember at the moment). It makes sense why it wouldn't give an assist.
You can give a speed boost to an ally, heal an ally, who dealt the killing blow and still receive assist gold. Azir gets assist when their allies walk though his wall. Riot explicitly gave him this utility in one of the patches.
The Question is Should Challenging smite Grant assists? Considering it provides a 20% damage Debuff, I would say yes.
I think saber should be looked at in general. it was changed to not favor auto attackers which WW ridiculously exploited. And yet I find that put in an awkward position. I mean, it suppose to be the dueling Jungler item. How can we give champs more dueling power without making it broken on already good duelists? The best I can come up with is certain Jungle tanks, who can clear some what fast. And definitely be able to use said smite to chase off invaders.