Oooh, this is hard.
Pewter would be really useful, and you can use it subtlety
Being a coinshot would be so awesome though
Lurcher has potential for a lot of utility, look at Ranette
Bendalloy is awesome, but I don’t know how easy it is to find bendalloy irl. (Is it even a real metal? I think so, but autocorrect doesn’t seem to)
Tin could be useful, subtle too
I wouldn’t choose any emotional ones, I don’t like manipulating people, and all the other ones I haven’t already named have little utility on their own.
I think I’d choose bendalloy if it turns out to be easier to find irl, then Coinshot, then Pewter