In some dark cellar, attempting to defend myself and protect an injured friend, I was flailing about with the only tools at hand: my abalone iron and dive knife. Each time metal met demon-flesh, the creature became visible, fleetingly, and I'd attempt to strike it again. I couldn't always see it, but I could feel it. The thing had fangs, claws, short wings, and a nasty disposition.
Scary, scary dream, but satisfying; my dive tools and I came through.