YMMV / Once Upon a Time S4 E21 "Operation Mongoose"

• Alternate Character Interpretation: For the Darkness. Was it really going after the first powerful magic user it saw? Or was it part of a Batman Gambit to get Emma to take the powers? The Darkness seems to take forever to actually consume Regina, which could be it just waiting for Emma to absorb it. Emma could theoretically be powerful enough to fight it off if it went for her directly. But she would certainly accept the powers to save someone else from the same fate in a heartbeat.
• Anti-Climax Boss:
  • Blackbeard becomes the first villain to be defeated by Henry. While this would not be much of a problem, the greatest pirate essentially got beaten because Henry cut a rope and knocked him out.
  • Lily is able to control her dragon form in this universe but she's easily defeated with a well-timed blast from the cannon.
• Awesome Art: In-Universe, the cover for "Heroes and Villains" looked really amazing.
• Draco in Leather Pants: As noted under What Do You Mean, It's Not Symbolic?, this could be viewed as a Deconstruction of this very trope. Villains who have done legitimately evil things get a Reality Warper to change things so that they are unambiguous heroes - just as fanfic writers do. Isaac likewise gives a Freudian Excuse for his behaviour, only for Snow to shoot him down completely - saying that having darkness in your heart is something to be pitied. What's more is that the whole point of Regina's character arc is less forgetting or dismissing the evil she did and instead her realizing she needs to change and do right in the future if she wants to Earn Her Happy Ending... and the whole reason Snow and Charming did what they did was because they were compelled to by the Reality Warper Author, again in just the same manner as fanfic authors forcing Ron the Death Eater in order to pull off a Draco in Leather Pants.
• Fanfic Fuel: Thanks to time contraints and the focus of the story, much of the extent of Isaac's world where villains win is left off-screen, as is exactly how the characters got to where we saw them. Between this and the number of available characters to have reversed lives, and there could be fodder for fanfics for years to come.
• Genius Bonus: The year that Isaac became The Author after the previous one passed away was 1966. Which famous author passed away in the same year? Walt Disney himself! The reference is even more specific; the letter Isaac received was dated December 15, 1966, the exact date of Walt Disney's death.
• Narm: When Henry is being attacked by the ogre. He calls out for help with the worst Dull Surprise ever.
• Special Effect Failure: The CGI for some of the places in the Heroes & Villains universe is really atrocious. It does help with the overall fakery of the place though.
• They Wasted a Perfectly Good Plot:
  • When Isaac tells Rumple his life is a lie, Rumple is faced with a difficult choice: keep the facade up or accept the truth. If you were thinking he'd actually do something redemptive like the self-sacrifice he did in Season 3A to keep his family safe from Pan, you'd be wrong. Isaac even lampshades this when he rather snidely says, "I know you'll make the right choice. You always do."
  • The entire concept of the Heroes and Villains Alternate Reality itself could have carried an entire season by itself with the heroes fighting against the villains and Isaac and struggling to set things right and with Rumple struggling with the truth and what he is which could have given him some more character development and an extended Redemption Arc. There's also some much more interesting world building that could have been explored - the fairies are said to ambush people in the woods, Granny working with Snow (is she still able to transform in this universe?) and Lily's origins.
  • Maleficent does not factor into this two-parter at all. Despite being heavily involved in the arc, she doesn't appear in the episodes and barely even gets mentioned.
• What Do You Mean, It's Not Symbolic?: This two parter could be considered a Take That! to the rise of alternate versions of classic tales that like to rewrite things with the heroes and villains swapped around. For example Maleficent turns Maleficent into a would-be rape victim at the hands of King Stefan (and ultimately a heroic figure), or Wicked which turns the Wicked Witch of the West into a Well-Intentioned Extremist and the Wizard of Oz into an evil dictator. In this universe the villains have become the heroes by getting someone to literally alter reality to make themselves seem sympathetic. Rather than attempting to Earn Your Happy Ending, they're trying to rig things so that they look like innocent victims by comparison.