Yep! Finally MLP art.
This battle took place many thousands of years before the current events. And it is not the final battle of good against Lord of Chaos.
Discord with his new favorite doll versus Celestia, on her burn of rage form: Lightmare Sun.
What do you think?Timeline:
Founding of Equestria ( "Hearth's Warming Eve" episode ) --> The conquest of the country by Discord. The reign of chaos. --> Bunt alicorn sisters and their allies against the Lord of Chaos --> This battle ( Fail )
--> The final battle with the all Elements of Harmony ( I think Celestia and Luna were users of a specific single item ). Discord Lost. --> Much later Nighmare Moon time --> Thousand years later, today time.