Xenon

Xenon is one of the elements on the periodic table. It’s found in the atmosphere,(and on Mars) so if you go high enough, you may be able to find xenon floating around. If you have an empty glass, you can capture it. If you do have Xenon, as well as glow stone, red stone, and a stick, you can make a UV high pressure arc(or UVHPA flashlight(since Xenon can make UV light in those type of flashlights), and it can deal damage over time. However, every 30 minutes of use, it must be connected to redstone for about 2 minutes.