Life's not fair, is it? For some, they try their best and still come across misfortune after misfortune within their daily lives. For others, they don't even deserve whatever cruel suffering the universe forces them to endure. Regardless of whether you're a good pony or not, you are nothing less but a prisoner of fate.
Such is the case with Ardent Cadenza. A pupil of Star-Swirl the Bearded that healed the sick and was the nicest unicorn one could ever hope to meet. But alas, fate does not care for those things, especially when it's in need of a force of darkness to balance out the light.
Partially based on an entry for Codex Equus that I wrote and is written for this story red reaper intends on making:
https://www.fimfiction.net/blog/867779/a-villain-group-story
And yes, Ardent's backstory is loosely based off of Ardyn Izunia's backstory from Final Fantasy XV.