The story I'm looking for, and can't for the LIFE of me remember the title OR author of, concerns Princess Celestia facing off against (and apparently losing(?) to) some human (I think? Not really sure if he is, or isn't; he's at least humanoid in form, anyway) would-be conqueror in the throne room (again, I think) of Canterlot Castle, where he and his soldiers have seemingly trapped her and are torturing her.

The only other thing I remember for sure is that it's definitely a one-shot fic, but other than that, details (form MY end) are a bit sketchy, but I would really like to find it and read it again.

Help? Please?

Thanks in advance, y'all.

7700690 There's one about Discord doing that:  Discord Sits on Celestia’s Throne

There's also a story about a human, who conquerers Celestia: The ̝̘̘̲̭̘͈̮͙̹̱͈̯̝̳R̷̥̙̰̤̲̪̭͖̺̣̙͈̲̀ͅi̗̥̺͉̜̲̮̝̻͉͕̬̋͗̑ͨ̽͛̀̇ͬ͌͊͟͡͠s̶̻̪̬͇̝͓͔̞̲̟̜̻͖͓͂̔̒̓́̽ͧ̓͐̓ͮ͘ē̛̙̖̣̳̇ͮ̒̿̄̅ͫͧͣ̄ ̵̨͈͎̪̦̦̣͌͗͋ͫ͌̊͗̈ͣͣ̈ͨͫ̀͋͛͘̕͠o̽͐ͪ̃͑̇͐̐ͫ̆ͥ͏̵̸̡̧̲f Insanity

Though, you probably meant some other story.

7700701 Yeah, it's neither one of those.

One thing that I forgot until just now is that Celestia mentions the "Power of the Individual" over the power of the many when she's talking to the enemy leader.

Part of me thinks that the story title is something like "The Power of One", or something similar.

Another thing that I remember now is that she seals them all (including herself) in the throne room, and sacrifices herself to blind the leader and incinerates pretty much everything and everything in the throne room, as well as destroying Canterlot itself, as I remember it ending up at the bottom of the mountain that it was on.

Don't know if that helps at all, or not, but I hope so.

Hmm.
No one else knows what I'm looking for?
Bummer.
Ah, well, it happens, but I shall keep looking.