Those are some hefty rolls, hopefully just doing that well is enough to get him to take us seriously.
I have a couple of thoughts here.
The first is to make something wholly mundane, but shaped to make it a cast iron bitch to effect with magic.
The other is to lean into how DF uses foci which aren't enchanted but do help a caster increase their own leverage to make something which itself isn't enchanted but makes a caster much more effective at something specific while using it to fill in for a weapon.
The specific inspiration I had for this was the importance of pentagrams in most DF magical traditions. They have a lot of heavy symbolic meaning in confining/directing power, along with circles.
Molly has already demonstrated the ability to make very exotic carbon structures, from gems to her fancy armor.
So consider the potential of
Fullerenes; specifically the varieties that can form dodecahedrons, flat planes of pentagons, or various connected elements creating atomic scale rings. There's also potentially something interesting to be done with nested structures containing cores of other elements and the symbolic value of rare materials.
For example:
In classic hermeticism fire and sulfur are closely associated, and the alchemical symbol is triangle.
Tungsten Sulfide is a compound that actually naturally forms triangular prisms at a molecular level.
If you want to throw fire at someone is there a better focus than a gem composed layers of runes/geometric shapes asserting the will of the caster over reality written in lines of perfect molecular scale pentagrams enclosing individual atoms of silver, all of which trace over a fractal rod symbolically invoking fire at every observable scale?
Seems like the sort of leverage you'd want to turn a spark's worth of effort into a death ray.
It's probably a bit of a reach, but I wanted to float the idea anyway because nanoscale magical engineering sounds like the sort of hilarious bullshit an exalt in a modern setting would try.
I get the frustration, I just think the solution is to expand our horizons and do things that engage with the setting as it stands.
They aren't powerful enough for our boss fights, but as long as the quest doesn't power scale to insane levels there is stuff they can do that is relevant. Social things for one, particularly related to other mortals.
Realistically the bosses we fight are always going to be a challenge, trying to chase everyone being that level isn't viable. That doesn't mean everything outside of the things that are really Molly's job to handle have the same requirements.