Mix some eyeshadow with an eyeliner or makeup sealer to turn any eyeshadow into eyeliner.
This can also work with water, but in my experience it doesn't last as long with just water. A great and cheap (also what I use) sealer is ELF Makeup Lock & Seal. It is this great little kit that comes with a little bottle of the Lock & Seal, a small mixing pot and a brush.
You can also mix any setting spray, such as Urban Decay All Nighter, or ELF Mist and Set with eyeshadow and get the same result.