I've been watching Stargate SG-1 lately. Artifacts don't have to be weapons. They're so much more fun for the DM when they aren't weapons. I mean look at Stargate. The entire premise of the show revolves around a single "artifact". Whichever DM came up with that idea is straight up genius. He even gets to throw down nearly any time period he can imagine. That still doesn't stop the players from treating the artifact poorly.
Picture is a screen capture from the Stargate SG-1 tv show