Prince Polaris Blueblood is an old stallion, but he hardly looks the part, at worst he can be described as 'stately' which hardly counts as an insult. Still he feels the wear, he feels the deaths of his friends and family, he feels the trauma that crashes is his skull. He decides to write it all down, his sins, his triumphs, his life, and his first death. He will have his ponies read it, and he will watch as they forget it over the centuries, he will watch as they forget all that was in favor of fantasizing of what will be.

TLDR: Alicorn Blueblood Writes a Memoir About His Life, It Sucks Hard, Like Just the Worst. Everyone is a Worse Version of Their Canon Selves.
Heavy inspiration from "The Blade Itself" and the rest of the First Law Trilogy by Joe Abercrombie
You Have Been Warned.