These large heavy dark black robes have a couple of interesting properties; the first of which is they are very sticky to weapons, and the second of which is a type of underwater action enhancer.
When attacked even the sharpest blades will stick and slow down entangled in the slowing magic of the cloth. It’s not an incredible effect, but it’s enough to throw even the most seasoned fighter into a bit of confusion. Subsequent attacks will occur at a negative, and with severe initiative penalty as well.
The second set of powers is more interesting, underwater the robes will adhere tightly to the skin and then the magic hidden in the fold changes it’s character; instead of sticking things up, you slice through the water. This allows you to swim at 8x normal speed. The constriction of the material does something odd to your breathing as well, although it you doesn’t let you breath underwater, the wearer will find that one breath will sustain them for upwards of twenty minutes. Also, when willed, the robe will leave a thin black streak of color in the water in whatever direction the swimmer has traveled; allowing others to follow.