What properties would make the best metal? (Fantasy Worldbuilding)
I'm writing a D&D campaign and am designing a central metal element that makes up everything (a lot of things), like Vibranium from Black Panther or something akin.
I know and understand all the regular stuff that's taught in school, what properties metals generally have as an element as well as the variety of different properties such as hardness v.s. toughness, ductility v.s. malleability etc, but I pretty much have the most basic understanding of all of it, everything you can get off a search engine. I am aware of contradictory properties (bendy metal good for wires, un-bendy metal good for manhole covers), but I would like to know what would be the "most useful" properties for a metal that could be applied to basically all of the roles metals would usually be found.
Is that possible, or would certain applications be too different for the same metal to be used in both applications? I'm talking everything from the most durable drills to the sharpest knives to the most protective helmets. It doesn't have to be something that could feasibly exist irl, I just want numbers that would make the material very good. If it does use real elements and you want to map out the structure it could have/how it would form, even better but no pressure, this is a worldbuilding experiment. Feel free to use any words and numbers in your response, I'll look up what they mean if I don't understand! I know the mohs hardness scale better than the others because I'm kinda into gems, I know what density is, I have since learned how to measure tensile strength. Thus far, I have learned many properties and potential issues from my initial search before this post (machinability, weldability, thermal diffusivity, sparking, galling, toxicity etc etc).
Alternatively, does this already exist? From what I can tell it probably can't exist, but there are a lot of very good alloys that are resistant to corrosion, extremely durable etc, which one would you pick if humanity could only use one type of metal/alloy forever? What properties would we sacrifice with your pick? If it is a steel alloy (because those are common and useful), what kind specifically and why?