To preface, this is my first attempt at a calc, so there will most likely be some mistakes.
Well feat is pretty straightforward. A full squadron of Doom Scythes can reduce an entire hive city to fulminating slag. We also get a nice size chart of how big hive cities are.
I used the formula for the volume of a cone. So h = 16.0934 km, r = 4.22 km. The formula is
V = π * r^2 * h/3
V = 3.14 * 4.22^2 * 16.0934/3
V = 300.12 km3 = 3.0012e+11 m3
80% hollowness would be 60024000000 m3
Hive cities are made out of "rockcrete", which is basically concrete, and adamantium, which is completely fictional. I'll use Drite's line of thinking here. So concrete has a density of 2400 kg/m3, specific heat capacity is 1000 J/kg*K. And we'll be using sand's boiling point, which is 1610 C.
60024000000 * 2400 = 1.440576e+14 kg
1.440576e+14 * 1000 * (1610-20) = 2.2905158e+20 J
Latent heat of fusion for sand is 156000 J/kg
1.440576e+14 * 156000 = 2.2472986e+19 J
2.2905158e+20 + 2.2472986e+19 = 2.5152457e+20 J
And since it takes an hour to do the feat we divide that by 3600, so
2.5152457e+20 / 3600 = 6.9867936e+16 J
And because this was done by a squadron, wikipedia tells us that a squadron consists between 12 and 24 aircraft. So we divide it by 12 and 24 so we get individual deathray output.
High-End: 6.9867936e+16 / 12 = 5.822328e+15 J or Low 7-B / Small City level
Low-End: 6.9867936e+16 / 24 = 2.911164e+15 J or High 7-C / Large Town level+