Time is a neutral party. It takes no sides, only proceeding without a care for those caught in its trap. That is how it should be...
But not all traps are foolproof.

When a pony seeking the Night Princess's counsel intervenes during an assassination attempt, Luna knew there was more to this stallion than met the eye.
However, even her expectations had limits. That, Luna discovered, was a mistake.

One question troubles her thoughts as a new problem presents itself in the form of this stallion; how does a heart and mind cope when one escapes the trap of time? What happens to a good heart when it is worn away, year after year, all stemming from a single mistake, no matter how good the intentions?

Equestria Daily seal of approval: https://www.equestriadaily.com/2019/11/fanfiction-timeless.html

Takes place during/after Season 9.
Sequel: Sunspots