[quote=Prince]
Shadow Imitation can easily chase down a target and relocate itself. But, once the Shadow Covers an area, the tendrils are summoned through it. Once tendrils are summoned, they cannot move. You can summon more, but they can't "shift" from their spot. I know it sounds like a tiny things, but I literally have had people chase down others with tendrils that are basically intangible, regrowing bits of blackness. It's a bit broken. So, for that purpose, I break it down into two steps: Placement of the Shadow, then creation of the tendrils.
[/quote]

Wait, intangible? That doesn't even work (so whomever was doing that was doing it wrong). Usage of Shadow Sewing creates the shadow as a tangible entity, allowing it to physically embed itself into flesh. This makes them blockable by weapons.

I still don't quite get the constraint you are trying to apply. So you are saying I have to extend my shadow and then form the physical tendril from that point and have the size, direction, and etc set? 

My suggestion for regulation on it would be to limit it to volume of the shadow and create a minimum width for the tendrils (a quarter of an inch or something).