Knight's & Magic and the power of honesty
Knight's & Magic doesn't exactly have a promising premise and plot; in fact, it basically sounds like a wince inducing piece of wish-fulfillment fanfiction. A mecha otaku dies and is reincarnated as a kid genius in a world with mecha where he can use his other-worldly ideas to make the best mecha ever and be fawned over by all and sundry? Many people would give such a show a wide berth. But despite this unpromising premise, the actual series was surprisingly good, with an infectiously earnest enthusiasm and a a heart-on-sleeve appeal.
Originally I was going to write about the power of this earnestness and embracing your genre, as Thunderbolt Fantasy did last year. But earnestness by itself doesn't make a show good in the way that Knight's & Magic is; there are plenty of quite earnest works that are actually kind of terrible, and Knight's & Magic could very easily have gone off the rails itself, falling into complete absurdity and losing much of its appeal. Instead, I've come to feel that the crucial ingredient that made the show work is honesty.
Knight's & Magic is a show that is honest with itself, and as part of that it's honest about what it is; it's wish fulfillment and it never pretends otherwise. Knight's & Magic takes things seriously (it's not a satire or a farce), but it's not a serious, realistic work and it doesn't try to be one. As part of this it quite deliberately dials everything up to at least ten, not for comedy but because it's more fun that way. While earnest fun is the heart of Knight's & Magic, I don't think it would have been possible if the people behind it had not understood and appreciated what it was, warts and all.
As part of dialing everything up to at least ten and going straight for fun, K&M is completely transparent about how the plot is on Ernesti's side. This is in a way another side of the show's honesty; the show is always clear about its fundamental nature, including its ultimate niceness (at least as far as the good guys are concerned, and this is a show with very clear good guys).
Another part of this is a surprising honesty about giant robots, because the final showdown is framed as the romanticism of giant robots versus the practicality of other options. Ernesti explicitly admits this and declares that he doesn't care; he's going to defeat Gojass's creation in order to preserve the world for giant robots because that's what he loves. He wins, of course, and it doesn't feel out of place because the thumb of the plot has been on his side all along and has never made any pretense about it. Knight's & Magic is as honest about loving giant robots, with their contradictions and all, as it is about the rest of its nature.
(You can read the ending of the show as partly a nod to this conflict being a never-ending one.)
Sidebar: Ignoring the long shadow of Gundam
Like many giant robot shows, Knight's & Magic winds up wanting to have its cake and eat it too. On the one hand, the most interesting giant robot fights are generally against other giant robots, and in situations where there is real tension. On the other hand this means war, literally; people are fighting each other in those giant robots and dying in those pretty explosions. The contradiction between war as a cool thing with awesome giant robots and the brutal, bloody consequences of war is deeply embedded in the genre since at least Gundam.
Knight's & Magic basically ignores this. It's not that it pretends that there aren't people dying in the pretty explosions (it's pretty explicit that there are, actually). Instead, it pretends that this is no different than when the characters were fighting giant monsters earlier in the series. The opponents are different and more challenging and the fights are cooler because they are giant robot versus giant robot (or giant robot versus giant flying robo-dragon), but that's it.
(To be fair to Knight's & Magic, the show also ignored how there were plenty of people dying 'heroically' against the giant monsters. It did have one little plot section about how scary fighting is, but promptly brushed it off.)
Within the show this pretense works, but that's by authorial fiat. Outside of the show, well, there's at least a long history of doing this and the audience is probably used to it. Knight's & Magic is not a show you think deeply about, anyway. I twitch here because I'm quietly scarred by Mobile Suit Gundam 0080: War in the Pocket.