>>1623
I think Flurry x Sombra can have potential, but I'm not a big fan of redeeming Sombra. His entire character seems to be "power-hungry slaver", using cruelty, inducing terrors with dark magic, etc. He seems completely devoid of empathy, and power-hungry and sadistic to the extreme.
Like, Nightmare Moon wanted to bring about eternal night and wanted to be loved. Chrysalis wanted to feed her children and not have them metamorphose into gay sissybugs. Even Tirek, who wanted power, wanted it basically just to be powerful and run around on roids; he only wanted to hurt other ponies insofar as he wanted to drain them of their power for himself. Selfish and power-hungry, but not sadistic. Meanwhile, in comparison, Sombra wanted power to
dominate. He literally enslaved with mind control the entire population of his empire. Allegedly in S9 his first act after being revived was to mind control everyone into being his slaves. He seems to want "power" less for raw strength, but rather more to be able to make everyone his subservient slaves, to strip them of all agency and rule over everyone else absolutely.
So there are various ways you can go with Sombra+Flurry, from full-on evil Flurry to some kind of middle ground where Sombra stops using sadistic terror spells and maybe even doesn't mind control everyone, but still rules with an iron hoof. I don't, however, really see it working with Sombra being redeemed enough to be "good" and actually working for the greater good of ponies. I really don't see a world where Sombra sees Equestria being weakened by Twilight's bullshit and, rather than rejoicing that it'll soon be in shambles and easy pickings to conquer and subjugate, instead fights to restore a strong pony nation. In general, "strong pony nation/populace" seems antithetical to his methods.