I have the soulbound weapon Nightshroud equipped on my priest. He's killed several humans (last hit, and solo) - yet the counter still reads 0/13. Anyone else having this issue? I saw similar threads for other weapons (St. Waidwen's Redeemer, etc...) but not Nightshroud

To update, I think the issue is the way enemies are categorized. For example, killing Skaenite cultists didn't count as "human." 

I think it's just the code is broke for weapons accumilating kills. 

The Redeemer has a proc that only procs vs Vessels, and the upgrade requirement is to kill 50 vessels with it... I've let Palladingina take out every mob I could find that it procs on and still don't have a single kill registered on the sword.

One thing I noticed was that if you kill someone by bashing them with a shield they will not count towards to kill count. Check to make sure you shield isn't stealing the kills

That's a good point - I'll look at it again today and confirm. I am pretty sure that it may be specific to the Skaen cultists as other human kills seem to be recording properly