TheCosmicKid
Hero
Forget for a moment about whether such an item is appropriate for 1st-level adventurers, because the game world doesn't know that the adventurers are 1st level and customize itself to fit their needs. The real question is: what is such a powerful artifact doing just lying around where 1st-level PCs can find it? Items like that are (under normal D&D assumptions) extremely rare and in very high demand. The weapon is more likely to be in the hands of a mighty fey lord or in guarded by a grove of obstreperous treants. If the PCs on their very first adventure just so happen to be in proximity to this item, what does that imply statistically about the density of such items of power on your world?
Imagine you're walking down the street. There's a diamond the size of your fist in the storm drain. You may search the storm drain and find it, or you may just walk on by. It doesn't really matter -- either way, this whole scenario is spectacularly improbable, because there are very few diamonds the size of your fist in the world, and the people who possess them tend to keep careful track of them. They don't often end up in storm drains.
Imagine you're walking down the street. There's a diamond the size of your fist in the storm drain. You may search the storm drain and find it, or you may just walk on by. It doesn't really matter -- either way, this whole scenario is spectacularly improbable, because there are very few diamonds the size of your fist in the world, and the people who possess them tend to keep careful track of them. They don't often end up in storm drains.