Here’s something I’ve been developing for the past week or so;

Human finds himself under the service of an AU King Sombra during a war between his conquered holdings and Equestria plus allies, with the former armed with an army of golem ponies made from dark crystal. The human, believing he has a debt to the king for saving his life, bestows the knowledge of heavier than air flight and its application unto the dark unicorn, as the war in the air has not gone well for said unicorn. Armed with what is essentially underpowered biplane drones/golems in the earlier half of the story, Sombra’s Crystal Empire grinds Equestria’s advance to a halt. Upon the discovery of a more potent fuel source, however, it is the Empire that begins to advance further and further at a seemingly unstoppable pace.

To limit what the human can influence, he can only give Sombra aircraft to use, as that is what he knows best. Golem magic works off of former knowledge and experience, which is usually why most golems are pony shaped, thus you can expect a lot of WW1 to WW2 era looking flying golems coming from the human. You won’t see T-34s any time soon, let alone any ground vehicle beyond simple transport or weaponized transport.

But unto the meat of it all; the human slowly starts to become corrupted, his sense of debt overriding his sense of morality. Ideas such as strategic bombing on cities and other civilian centers go from personal “no go” to needed necessity for the war effort, and the same thing happens to his point of view of Sombra’s slaves. It all comes to a head when he nearly wipes out the Caribou, using bombing raids armed with Tiberium like crystals to turn their lands into nothing but tundra. This leads to the end of the war, with Equestria’s remaining allies pulling out and overall war fatigue kicking in.

It should be noted this story is not anthro, but as to why the Caribou; given the nature of their commonly depicted culture (anything not male is a slave to be used), the human will try to internally justify is blatant genocide, further corrupting him. Hell, not even Sombra would have done such an evil act.

The latter half of the story will focus on the human after the Crystal Empire returns to modern Equestria, seeing as the sisters used some underhanded tactics to finally banish the dark unicorn. However, with no sign of Sombra returning in this case, the human is left to rule the Crystal Empire and defend its holdings, and to put bluntly he sucks at it. Thus, he attempts to pull an Argentina and flee, though whether or not he’s captured or truly escapes I have yet to decide.

What do yah think, eh?

Why exactly would you include a Tiberium-like substance? Is this a command and conquer crossover? If so, why is technology being based on early bi-planes, instead of more effective aerodynamic machines? This concept feels like a mess overall and Sombra hardly feels like a villain that would use this approach. Chrysalis or the original Grogar seem more like the kind of characters to rescue and befriend a ptentially informative human. =/

7287655

It’s not literal tiberium, more along the lines of corrupted magic crystal that acts in a similar manner. Though while tiberium can be refined and put to other use, this crystal can’t, as its only use is to leech the life out of the earth. It is a terror weapon. As to “befriending”; Sombra sees the human as a tool and subject, nothing more or less. He only holds the human’s loyalty out of said human’s sense of debt to him.

7287659
I think that's a less interesting angle to approach. An example of this kinda story was the Robocop reboot, where the Scientist just keeps letting his morals get corrupted until the very end. And we can all agree that, that movie was inferior to the original Robocop.