I'll go way out on a limb BEFORE the rules/contest are even posted
how to incorporate your sheath as a functioning part of your kit (besides it's primary purpose of keeping your knife handy and it and you safe)
I took my Landi PSK and wanted to use it in a neck carry. I wanted to insure it wouldn't strangle me in a fall/tumble so I found a little plastic piece that is tough, but not nearly as tough as the cordage so it would break first. I'm using 2 mm Spectra cord as it's in the 200 # range, which is plenty for it's intended use as cordage for lean-tos, debris shelters, etc. It's lighter and you can carry more for the same volume.
I wrapped ~ 15' of the 2 mm stuff around the sheath, within that wrapping I secreted a small 3/16" firesteel. I added a Fox micro whistle and Photon light. I found them rattling a bit, a small ranger band cured that.
I wanted to insure the knife would not come out (it probably wouldn't as the kydex is well molded to the knife, but an extra safety measure) so I made a short lanyard w/ a plastic toggle that can be secured over the sheath preventing the knife from coming out.
the entire kit (knife, sheath, cordage, light, whistle, lanyard/hardware) weighs a svelt 4.7 oz
now if I happened to entirely miss the point of the contest I'll simply edit my post so I don't look like an idiot, but if I haven't- points for putting the clues together- here's hoping for the latter