The Star Wars influence is strong in this one, but the readers who had an eye out for it could probably see the Metal Gear influence creeping back in as well. This story arc is a convergence point for several things Flo loved about the series: the Metal Gear riffs, gnomish culture, and military plots with more than a passing nod to logistics. From her script:

The Ultimate Engine is the final thesis statement on the Mecha-Tank arms race that has characterized the progression of warfare in Arkerra. Although it much more resembles a proper tank than would otherwise typically do. The “Body” is shorter and wider, providing better armor and stability than before. All of its plating seems thicker, reinforced. It is at least 1.5 times the size, overall, of Taro’s first tank from Chapter 14.

It is in all ways the improved version of the classic concept, where the left and right arms now have quite menacing pincer-claws, featuring two extra points of articulation on the arms than previously for even more versatile combat options. The schematics indicate that pop-out buzz saws are available in the front of the tank, a la Speed Racer’s Mach 5.

The most noteworthy feature, however, is the large rail gun on its back. Its design looks gnomish, but it clearly has its power source made in the form of Sky Elven Crystals. A diagram on the schemata nearby this rail gun, which looms over its entire body, indicates a smaller tank with a parabolic arc leading to a mushroom cloud.

Me, I’m here for Reynolds’ explosion in the last frame. It’s a very well-earned character moment, the portrait of a patient, cheerful optimist who has finally seen his values trampled on one time too many.