Role Play / Deadly Mistakes
This isn't even close to being everyone. Top to bottom, left to right 
Have you ever messed with one of those silly 12-character memes and gotten a "what if character X got character Y pregnant?" question, and then wondered what would have happened if that child was actually born?

The intrepid weirdos of a certain Fanfiction.Net forum did. And this is the RP (found here) they created based on that idea.

Then a few members of that group of intrepid weirdos turned out to be jerks and Gamergaters, so then a big bad SJW stole the RP along with all the decent members.

And then the group made a Wiki!

Now has its own Shout Out page.

Deadly Mistakes includes examples of:

  • Badass Family: Since nearly all of the characters are crossover kids, there are a lot of these.
  • Beauty, Brains and Brawn: Can apply to several trios in the main cast.
    • Kainashi, Yuuka (perhaps interchangeably with each other) and Nan respectively.
    • Inochitori, Rowan and Jasper.
    • Eve Halle, The Professor and Serena.
  • Big Bad Duumvirate: The Master II and The Blue Hood teaming up in the second arc.
  • Bonus Boss: At the motel, the Snow King was going to be this to The Professor if The Professor did not tread carefully enough with him beforehand.
  • Break Them by Talking: What the Mistakes have to do with most Fetters.
  • Breaking the Fourth Wall: Yuuka did this subtly in Chester's lab by acknowledging the roleplayer of the upcoming Big Bad.
  • Breather Episode:
    • The Mistakes' lunch outing at the combination Chinese-And-Japanese restaurant. Of course, shortly after they ran into Eve Halle, but...
    • Meeting Chester, Swallow, Jewel and Princess Candy at Chester's lab after pacifying the Snow King.
  • Call-Back: The plan to perform sentry duty at the motel is a call back to when the Mistakes kept watch in shift at Thaddeus' house back in the original timeline.
  • Character Development: Happens for most if not all of the Mistakes, but especially the ones with Fetters.
  • Character-Magnetic Team
  • Four-Philosophy Ensemble
    • The Cynic: Kainashi, Canaria, Alvan, [WIP]
    • The Optimist: Wren, Ayame, Prism, Jacqueline [WIP]
    • The Realist: Yuuka, Nan, Belial, Claude, Ryou [WIP]
    • The Apathetic: Demasiado seemingly, Corinne, [WIP]
  • Four-Temperament Ensemble
    • Sanguine: Yuuka, Demasiado, Ayame, Prism, Heather, Jacqueline, [WIP]
    • Melancholic: Nan, Canaria, Isaac, [WIP]
    • Phlegmatic: Wren, Belial, Ryou [WIP]
    • Choleric: Kainashi, Claude, Corinne, Grammaire[WIP]
  • Enemy Without: The Fetters.
  • Hitchhiker Heroes
  • Loads and Loads of Characters
  • Mad Scientist Laboratory: Chester and Jewel have at least one.
  • The Psycho Rangers: Actually did appear canonically, as minions of The Master II.
  • Ragtag Bunch of Misfits
  • Those Two Bad Guys: The Master II and Nan used to be this in the first arc.
  • Wire Dilemma: Happened when Rowan, Yuuka and Isaac had to deactivate The Master II's Genesis Bomb.