This story is a sequel to The Sun Burns Brightly
When you're the immortal ruler of an entire kingdom, the most important quality to possess is a passion for your work. No princess can rule her nation if she can't find it in herself to give her best effort every day and night. Luna knows this better than anypony, and puts her whole heart into everything she does.
But passion, unless tempered by restraint, has a way of biting one in the flank.