Note on da nuclear howitzer:
I did some napkin-math. Apparently that 0.1 radian cone translates to about 5% of the range to the target becoming the radius of the area affected. For example, at 1km distant, the expanding cone would pass through a circle approximately 104 meters in diameter (52m radius), for a nuke that's pretty ridiculous targeting power. You wanna fire from the edge of space? That's 100,000m and gives you a target radius of 5.2km (ignoring atmospheric effects because fuck knows what that'd do over 100km distance), though that's only what's affected by the 85% of the blast that gets directed, the other 15% turns the casing and fission products into a spherically-expanding ball of mixed-element plasma and maybe an EMP.
But enough of that obsession. I'm sure I can dream up something insane of my own to fire at the supernatural legions. Hmm... for awe-inspiring energies I probably want to go nuclear, oh! If we get really sci-fi maybe we can start messing with the Higgs and gravity... wait, I think i got one!
How's this sound? You set up specialized speakers at a bunch of different points and modify the frequency of each of them so that at the 'target point' all the wavelengths constructively interfere and give you a sonic blast of compressed air and stuff... nah, that's too low energy and the range would probably suck, though it could blow out ear-drums and air-bladders at low frequencies and higher amplitudes, maybe burst some blood vessels in lungs? Hmm.
Oh! This one's completely theoretical but I heard about something called stimulated gamma emission of nuclear isomers. Its got one shitty and much-debated experiment to its name so is probably not a real thing, but the idea goes that you take one or two specific isotopes of specific elements and irradiate them, when the right frequency, or right combination of frequencies, hit a nucleus, the theory goes that it forces the protons and neutrons into a different arrangement that is higher energy but still somewhat stable (called an isomer). Ordinarily samples of it then decay over time, emitting a gamma ray when they fall back to the base state, but the half life is so long that it's only a weakly radioactive substance. The way this becomes useful is if a specific frequency of EM radiation can stimulate the nuclei to decay on-command (and the most controversial part of the experiment) the thinking went that if you could energize whatever isotope it was that had stable isomers and then set up an EM emitter of specific frequency (could be a laser if the desired wavelength was right) pointed at it, you could have either A. Batteries with nuclear power densities (approx 1 million x that of traditional chemical ones) or B. nuclear hand-grenades (remember, large numbers of gamma rays have a tendency to hit air and heat it up, making explosions)