My personal favorite is the shardbrella.
Basically the point is that a windrunner could use it to fly through something like an airship or a building.
The shardbrella is formed with a long spear-like handle, which ends in an umbrella or top like cap, creating a shielded space underneath. The point of the shardbrella is sharpened enough to cut. Likewise four bladed points come from the point and create a bladed ring a few inches further out from the ends shardbrella. Now to finish it off we just add tiny blades running along the sides of the shardbrella.
I really don't know if I explained that well, but the idea is that at the top there is a point and a ring of blades that would look like this
Anything that gets hit has a circle removed from it the size of a person, and that circle that is cut out is torn in four pieces, which is further shreaded apart until it is harmlessly dropped past the person holding it like fine confetti
Here's what it would look like from the side
If that makes no sense at all please tell me, and I'll find a way to explain better.
The reason Focused ones are resistant to shardblads isn't invesitutre. It's that their bodies are so dense that once the point/blade gets past the skin the rest of the skin holds the metal and prevents the blade from going deeper. That's why Sigzil could kill them if he was going fast enough.
Fun fact: you can do the same thing with cheese