User blog comment:JmLyan/Zelun, the Crowd Herder/@comment-4948122-20130528170906/@comment-7481207-20130529075907

When you multiply with a percentage, as with the slow potency, it works the same as if you would multiply with its corresponding decimal value. So 1 * 40% is the same thing as 1 * 0,4.

And while the Q might be a bit inconsistent, it can be planned just like Annie's passive can be. Just cast it on minions until you get the desired effect on your next cast.