YMMV / Diaries of a Madman

• Diagnosed by the Audience: It's not exactly clear what Luna's issues are. An Ax-Crazy psychopath with traits of a Narcissist. Either way, the mare has some problems.
• Fan-Preferred Couple: There are quite a few of them floating around. Nav x Spike, Nav x Fluttershy, and Nav x Celestia are the most prominent, though.
• Growing the Beard: The story really starts to hit its stride about 32 chapters in. The author himself agrees that the story gets much better later on, and viewed the first 12 chapters as so bad that they underwent a complete rewrite.
• Ho Yay: Copious amounts at times between Nav and Ames, and later Nav and Spike. The shippers noticed.
• Hilarious in Hindsight: In this story, cats rule Egypt. In the official comics, we're introduced to Anugypt, which is ruled by, you guessed it, cats.
• Jerkass Woobie Nav. While it is true he has been thrown into a world he'll never completely fit in with due to his past self pissing off Discord, and has been tortured, raped, lied to, used as a pawn and even those he calls his closest friends have a habit of letting him down. And like the princesses, he also lives to see everything he's ever known destroyed by Discord. However. There is one thing that everyone, even the readers seem to forget: The guy is practically a Hate Sink. He's a Hypocrite, a Jerkass, he's racist and sexist, stubborn to a fault, he kills and tortures for little to no reason, he never learns from his mistakes, and he refuses to accept any attempts to get him to change.
• Moral Event Horizon: Discord causing the near extinction of the alicorn race and being (in)directly responsible for the extinction of humanity.
• Ship-to-Ship Combat: For every fan of a particular ship, you can probably find others who will strongly disagree and find it a to be a terrible idea.
• Too Bleak, Stopped Caring: With most of the protagonists being almost as villainous as the actual villains, a main character who is incredibly unlikable, (and never gets called out on it) the world being much much darker than in canon and even members of the main six doing morally ambiguous things it can be very hard for some people to get invested in this story.
• The Woobie:
  • The entire alicorn race, tortured, mutated, and destroyed at the hands of Discord.
  • The fate of Moonbeam, better known as Chrysalis. A kind-hearted midwife and Friend to All Children, perverted into a monster by Discord.
  • The princesses, and especially Celestia. After having their home, parents, and entire civilization destroyed, they're forced to take up a role they never wanted, while their life expectancy makes it hard for them to form connections due to the discrepancy.