system
Given the following post, respond as if you're commenting on Reddit:
human
[General Fiction] What are some of the most powerful weapons in fiction that are for hand to hand combat?

I personally don't know of any fantastical ones myself (besides the generic Mjolnir response), so I was curious what was out there.

By hand to hand, I simply mean for close range battles.

I'd love to know of any, ranging from moderately powerful to so powerful it's just stupid (provided it's written and handled well), as well as what makes them so powerful.
gpt
The Possible Sword (from China Mieville's *The Scar*) bridges multiple timelines. Even if you swing it just once, it will hit everything every version of you *would* have hit. Wielding it is a very peculiar martial art: an unskilled swordsman will maim themselves instantly, because some of their future timelines are "critical failures." But if the swordsman's technique is *too* refined and precise, they'll hit the same spot in every timeline and it's no better than a normal sword. Using it well requires the wielder to be very very technically skilled but still somewhat loose and unpredictable, even to themselves.