[quote=@AtomicNut]

3-Silver won't be extra effective against all supernals, just [i]some[/i] of them (the kind that pees on signposts and howls at the moon and dislikes vampires, mostly). Luckily silver does have purifying properties, so it will screw some witches' black magic. Cold pure iron is also another good anti-supernal alloy that works against other supernal types. Anyway, bottom line is: If there was a single unified weakness, fighting would have been much easier so it's a no go.


[/quote]

What about a cold iron core jacketed with silver. Might be a bit expensive but I think I heard somewhere silver has decent enough friction which could make it a decent option for jacketing.