|Origin||OC created by Sarah Cowan|
|Original Name||Sarah Cowan|
|Home World||Twilight Town (possibly)|
|Weapon||Keyblades, Fists, Legs|
|English Voice||Sarah Cowan|
|Japanese Voice||Juri Miyazawa|
Sarah Serenity is an original character who will first appear in Kingdom Hearts: The Third Ragnarok. She is a fictionalization of Sarah Cowan, creator of "Kairi Eats Hearts", as well as a new iteration of the recurring character, Princess Sarah, from the Final Fantasy series.
After Empress Hazel defeated Sora and Riku and left for Far Far Away, Sarah appeared on Destiny Islands, looking for Sora. Kairi tells Sarah what happened and offers to help her find Sora, which she begrudgingly accepts. Later, Sarah finds Sora in Neo Asgard-III, just as it had been occupied by Hazel, and helps him beat Loki before introducing herself. They discover that Hazel has agents in the neighboring eight worlds, but are only able to go to four of them to seal their keyholes.
Sarah's appearance is basically a Tetsuya Nomura-style caricature of her real-life counterpart and voice actress, with a slightly bigger bust and more shapely figure. She wears multiple outfits in between appearances, including those of other characters like Tifa Lockhart.
- Tifa Lockhart (FFVII & FFVII:AC)
- Rinoa Heartilly (FFVIII)
- Yuna (FFX-2)
- Darla Dixon (an OC conceptualized for The Walking Dead by Sarah Cowan)
- Kasumi (Dead or Alive)
- Kokoro (Dead or Alive)
- Hitomi (Dead or Alive)
Also, in some of the worlds she visits with Sora, Sarah's outfit or appearance changes as follows:
- Poultry Prison: Aardman-style goose/swan with her Darla Dixon attire.
- Ratropolis: Aardman-style rat with her Darla Dixon attire.
- El Dorado: Marle outfit
- Mythic Ocean: Nami outfit
- Monster/Alien Battlegrounds: Lucca outfit
- Metro City: Princess Ranger (based by designs by Jamie Noguchi)
- Berk: Irina Sykes outfit
- Croodlands: Ayla outfit
Sarah is something of a multi-layered character with a strong dislike for Kairi, a trait of which she is rather outspoken, yet exhibits positive qualities such as bravery, compassion, wittiness, a desire to help her family, valuing friendship, maintaining a bright and cheery demeanor, and a dislike for bullying and disciplinarianism. She also idolizes and has a big crush on Sora, often flirting with him playfully or fantasizing about him, and desires to be strong for him and marry him despite his commitment to Kairi. Her favorite hobbies include cosplaying, gaming, modeling, singing, sewing, and writing romantic fan fiction involving herself and Sora.
Sarah is also autistic, meaning she has trouble giving attention to certain subjects, and does not respond very quickly, though it's usually because she wants to think carefully before she speaks her mind. Her autism does not, however, inhibit her optimism, and Sora shows her the utmost sympathy in light of this.
Despite her hate for Kairi, Sarah refuses to attack her, at least physically, and accepted whatever help Kairi could provide in finding Sora's whereabouts, since they both refuse to believe the recent rumors of Sora's supposed "death".
- "Eight Princess of Light! Sarah Serenity!" - announcement
- "What I want most in life is to love and be loved in return......to be happy and bring happiness to those I love."
- "So what are you, the estranged cousin of Rita Repulsa?" - to Hazel
- "Don't be scared, be hopeful."
- "If you give up now, then the battle is already lost."
- "You wouldn't know fun if it took a dump on your face!"
- "What am I, the human iPhone!? Stop bossing me around!"
- "Zorro called, he wants his sword, hat, cape, belt, and boots back!" - teasing Puss in Boots.
- "I'm Darla Dixon, y'all!!!"
- "I don't need a weapon to fight! And my friends aren't the only source of my true power!!"
- Sarah's relation with Kairi is extremely similar to that between Squidward Tentacles and Spongebob Squarepants. Also, the running gag about her wanting to marry Sora despite his inhibitions is exactly the same as Amy Rose's own infatuation with Sonic the Hedgehog.
- Her seiyuu, Juri Miyazawa, was on Seijuu Sentai Gingaman(one of GokaiWhite's favorite Super Sentai seasons) as Saya/Ginga Pink.
- Her dressing up as Final Fantasy and Dead or Alive characters is an homage to the fan series Dead Fantasy, which GokaiWhite is now interested in continuing or rebooting. Either way, he hopes to include Sarah as a main character.
- If Sarah is considered a Disney Princess (by proxy), then she would be the first one with a mental disability.
- Owing to her habit of making pop-culture references, Sarah sometimes addresses various characters by the following nicknames, based other characters with the same voice actors:
- Miguel: Captain Phoebus, or Mr. Fischoeder from Bob's Burgers
- Kale: Mr. Allstate (Dennis Haysbert is the spokesperson for Allstate in real life)
- Eris: Catwoman, or Aerith(because of how her name was translated to the phonetically similar "Aeris" in early english releases of Final Fantasy VII)
- Rocky(Chicken Run): John Smith, Mad Max, or Braveheart (Mel Gibson starred in both those latter films)
- Roddy: Wolverine, or bub(Wolverine calls a lot of people this)
- Spike(Flushed Away): Gollum from Lord of the Rings(she also calls him "precious" in reference to Gollum's famous quote)
- The Toad: Magneto, or Gandalf
- Missing Link: BoJack Horseman, or Batman in The Lego Movie
- Derek Dietl: Ant Man, or Brian Fantanna from Anchorman
- Megamind: Ricky Bobby from Talladega Nights, or Ron Burgundy from Anchorman
- The Warden: J. Jonah Jameson, or Cave Johnson from Portal 2.
- Guy(The Croods): Deadpool, or Van Wilder
- Yondu: Merle Dixon from The Walking Dead
- Merle's younger brother Daryl Dixon is often referenced by Sarah as another of her idols, and she has a picture of Jikanmu(also played by Norman Reedus) in her notebook.
- Sarah also paraphrases Yondu's famous "Mary Poppins" quote from Guardians of the Galaxy Vol.2.