Ideas 2 electric boogaloo?

So my neurons bumped into each other and made an idea. I don't want it so i'm giving them out free of charge

Diplomacy centered story

Core concepts:
Differences in Solar, Lunar, and Crystal guards
The Crystal empire war & Sombra negotiating W/ Equestria

General Plot Pillars(?)
Sombra somehow managing to get non-mind controlled crystal guard to cooperate
Crystal guard fending off the combined forces of lunar/solar guards while negotiations take place
Sombra Aiming to get out alive at whatever cost to himself (or others ofc)
The Negotiations of surrender on sombra's side (though the war is at a stalemate, it would be heavily weighted in sombras favor for obvious reasons)
Trade-off of mind control magic and its limits (Ie justifying why Sombra Needed the Skills of the crystal guard over any of his mind controlled legions)

General Structure(?)
Starts With Sombra Showing at a agreed meeting place and being shown around
(likely with the lunar guard fumbling against the crystal guard in the background)
The two parties settle in, as the princesses discuss the failure of the lunar guard's trap, decide to reassess the situation
(meanwhile plan B through Z are still lined up for the solar and lunar guard)
meanwhile, some of the crystal guard converse with each other, (blowing the act of being mind controlled if overheard)

Worldbuilding/Hie

Core Concepts
Magics and how utterly permeated the entire world is in it
what immunity means from a larger standpoint
What introduction of a true neutral would do to a world painted in black-and-white

General Plot Pillars(?)
The reason equestria has a villain problem is due to harmony(Balance) skewing everything to good/evil.
The Immunity to magic in main character(human probably best for the job) leading them to be a greatly destabilizing force to harmony(balance)
Magic being a Negative sum game. (Magic being another energy that can be converted from and too) And the incapability to covert normal energies into magic

General Structure(?)
Go ham, ive got no ideas here