Cthulhu Mythos Crossovers
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Shadows Over Fuuka by DrummondType2
Mai-HiME reimagined as a part of the Cthulhu Mythos.
Crossover - Mai HiME & Cthulhu Mythos - Rated: T - English - Horror/Supernatural - Chapters: 6 - Words: 12,753 - Favs: 2 - Follows: 2 - Updated: 49m - Published: 5/13 - [Natsuki K., Shizuru F.] Mai T., Mikoto M.
Eldritch Dragon Slayer by Hakimaster38 reviews
The multiverse is an interesting place, one of infinite possibilities. One of these possibilities became reality when a young dragon slayer discovers a tome of forbidden knowledge that sends the world of earthland on a downward spiral through the realms of depravity, anguish and insanity that is beyond mortal understanding.
Crossover - Cthulhu Mythos & Fairy Tail - Rated: M - English - Mystery/Sci-Fi - Chapters: 6 - Words: 26,885 - Reviews: 1 - Favs: 13 - Follows: 10 - Updated: 5/23 - Published: 4/7 - Wendy M., Carla
Fate Extra : The Music of the Spheres by celian Cogitore reviews
And in its dark ages, even death can die... 2099, a tragic time, a world ravaged by war and where corruption reigns. As the end of the world seems imminent, a hibernation capsule containing the last Master reappears. With the awakening of Hakuno Kishinami a new Grail War begins!
Crossover - Fate/stay night & Cthulhu Mythos - Rated: M - English - Supernatural/Sci-Fi - Chapters: 37 - Words: 175,564 - Reviews: 69 - Favs: 91 - Follows: 105 - Updated: 5/16 - Published: 1/23/2020 - [Hakuno K., Tamamo] Gilles de Rais/Bluebeard, Jeanne d'Arc
Child of the Crawling Chaos by Alias001 reviews
No true summary yet. Eldritch stuff. Fem(?)Harry.
Crossover - Harry Potter & Cthulhu Mythos - Rated: M - English - Adventure/Supernatural - Chapters: 3 - Words: 1,521 - Reviews: 3 - Favs: 63 - Follows: 86 - Updated: 5/16 - Published: 5/4 - Harry P.
Stories, Rewritten by DarkEmpress239
A rewrite of an earlier work on Ao3 that I orphaned. It's a story a chapter. Fandoms tagged aren't the only fandoms, hence the fandom being in the chapter title (FFN sucks in the multifandom department). The inspiration is at the top of the chapter, and explanation at the bottom.
Crossover - Harry Potter & Cthulhu Mythos - Rated: T - English - Tragedy/Horror - Chapters: 5 - Words: 1,227 - Published: 5/14 - OC
RWBY Noir by Wombag1786 reviews
"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its content." In 1919, the world has seen the horrors of the great war come to an end, yet forces behind the vale of sanity work and worm into the booming new world. Thankfully, humanity will not be alone in this madness. Though Madness, may prove to be a Blessing then Sanity.
Crossover - Cthulhu Mythos & RWBY - Rated: M - English - Mystery/Horror - Chapters: 43 - Words: 354,735 - Reviews: 165 - Favs: 80 - Follows: 90 - Updated: 5/9 - Published: 10/16/2019 - OC, Team RWBY, Team RNJR
Jaune'Arc - Hafh'drn ot N'gha Tharanak by Gavenga323 reviews
It wasn't supposed to be here. But it was here, inside his head. It always had been. Now Jaune has to go around the world hunting that which only he understands. But it could be worse, at least he didn't have to wait for the stars to align. 'Ain't that right, Nyarlathotep' 'You gave yourself this job, boy, don't look at me in that tone of voice.' M for violence, language & CTHULHU!
Crossover - Cthulhu Mythos & RWBY - Rated: M - English - Humor/Adventure - Chapters: 6 - Words: 75,969 - Reviews: 122 - Favs: 503 - Follows: 620 - Updated: 5/1 - Published: 7/8/2020 - Jaune A.
A Snake Called Nyarlathotep by Daemon-Sultan reviews
In London, four very different people team up on a jewel heist, then try to double-cross one another for the loot- wait, wrong, uh, everything. When High-Pharaoh Nyaralthotep is summoned by a cult to do their dirty work, he finds himself thrust into a universe where Dumbledore is an evil idiot, the Weasleys are scheming, Harry Potter is female, and Hermione is a terrible person.
Crossover - Harry Potter & Cthulhu Mythos - Rated: M - English - Parody/Humor - Chapters: 3 - Words: 22,388 - Reviews: 2 - Favs: 36 - Follows: 52 - Updated: 4/19 - Published: 3/2 - Harry P., Draco M., George W., Fred W.
Paranoid Ramblings by Entropy Vex
Just the half mad rambling of a paranoid insomniac and other miscellaneous things. (Initial chapter is a repost)
Crossover - X-overs & Cthulhu Mythos - Rated: T - English - Supernatural/Horror - Chapters: 1 - Words: 155 - Favs: 1 - Follows: 1 - Published: 4/5
Le rêveur by AvaTarbleu reviews
D'abord un arbre, ensuite un lac, les scènes s'enchaînent et Loki fait de mauvais rêves.
Crossover - Prisoners & Cthulhu Mythos - Rated: T - French - Crime - Chapters: 16 - Words: 12,548 - Reviews: 30 - Favs: 1 - Follows: 2 - Updated: 4/5 - Published: 1/10/2021 - D. Loki
What Rests Above, Rest Below by Zeroraid reviews
A huntsman dropout and a runaway, Alastor has no real idea what he's doing or where's going. All he knows is that beyond Argus there's Grimm, the White Fang and Human Supremacists somewhere down the road. Sadly, given what dad's last book says, those might not be the worst things out there. How is it that he's just noticing that the ocean is singing and the stars are whispering?
Crossover - Cthulhu Mythos & RWBY - Rated: M - English - Supernatural/Sci-Fi - Chapters: 1 - Words: 5,547 - Reviews: 1 - Favs: 7 - Follows: 8 - Published: 3/21 - OC
The Bored Outer God II: Through the Gate by Daemon-Sultan reviews
In 2081, a gate mysteriously opens in Santa Maria, a city in the Antarctic Dominion's Province of Naashoth. Out of it comes an opportunity, a casus beli, a chance for the great Antarctian war machine to move once again.
Crossover - Cthulhu Mythos & Gate - Jietai Kare no Chi nite, Kaku Tatakeri - Rated: M - English - Horror/Humor - Chapters: 4 - Words: 28,490 - Reviews: 3 - Favs: 28 - Follows: 36 - Updated: 3/18 - Published: 10/18/2021 - Pina
Mythos Effect by Omniscent1 reviews
A crossover between Mass Effect and Cthulhutech. Humanity has won the Aeon War and has since expanded and thrived. How will the galaxy fare with this new power?
Crossover - Cthulhu Mythos & Mass Effect - Rated: M - English - Sci-Fi/Adventure - Chapters: 24 - Words: 181,467 - Reviews: 1574 - Favs: 4,343 - Follows: 5,036 - Updated: 3/16 - Published: 6/5/2013 - Saren A., Shepard, OC
Seekers of Remnant by Zeroraid reviews
He wasn't supposed to be here, not in this world - this shard of reality. But here he was, a Seeker upon a world abandoned by its own Gods and now held by One best unseen. Remnant has him now, and he knows how it's story is "supposed" to play out. That doesn't mean its going to. The Old One has changed the script, and the Seeker has his own little edits to make to it.
Crossover - Cthulhu Mythos & RWBY - Rated: M - English - Horror/Adventure - Chapters: 6 - Words: 16,040 - Reviews: 7 - Favs: 45 - Follows: 57 - Updated: 3/15 - Published: 10/17/2021 - OC, Neo, Team RWBY
Weak Man's Apotheosis by Isbrandir Blake reviews
The crawling caos, Nyarlathotep, is no stranger to family and love ( love is more real than most laws of reality anyway ). But after an unprecedented event his family life will change a lot. For Izuku is the best thing that could have happened. # Azathoth best grandpa
Crossover - Cthulhu Mythos & My Hero Academia/僕のヒーローアカデミア - Rated: K+ - English - Supernatural/Family - Chapters: 26 - Words: 22,267 - Reviews: 6 - Favs: 28 - Follows: 33 - Updated: 3/13 - Published: 2/28 - Izuku M., Inko M., Hisashi M.
Xenos in Yellow by Hakimaster38 reviews
After a cataclysmic battle with his half brother, and a 10 million year nap the King in Yellow awakens to find a world where god's walk among mortals. What is a shepherd to do when they've lost their sheep, but find them and where better than the dungeon. It's his castle after all.
Crossover - Dungeon ni Deai o Motomeru no wa Machigatte Iru Darou ka & Cthulhu Mythos - Rated: T - English - Mystery/Sci-Fi - Chapters: 6 - Words: 28,105 - Reviews: 11 - Favs: 41 - Follows: 46 - Updated: 3/3 - Published: 2/10 - Wiene, Ray, Bell C. - Complete
The Horror at Hogwarts by emscribblings reviews
In 1942, three students disappeared, their bodies never found. The handful of survivors refused to speak of what had occurred, and the truth remained buried and forgotten. In his final days, the reclusive Abraxas Malfoy wrote down the damning words of his tale. Of a time when he pursued immortality and power alongside Tom Riddle — one of the vanished.
Crossover - Harry Potter & Cthulhu Mythos - Rated: T - English - Horror/Fantasy - Chapters: 1 - Words: 15,974 - Reviews: 3 - Favs: 25 - Follows: 10 - Published: 2/4 - Tom R. Jr., Abraxas M. - Complete
Lovecraftian Error by Anonymous Wandmaker reviews
In 1993, deep in the Department of Mysteries, an experiment goes wrong & monsters gain a foothold past the barriers that separate the human world from the other realm and begin to wreck havoc subtly. In Hogwarts, 2 unassuming girls, Sally Anne & Luna start to realize something is wrong, & because of how it affects them, try to find a way to right things. PostingOnRoyalRoad.
Crossover - Harry Potter & Cthulhu Mythos - Rated: K+ - English - Mystery/Adventure - Chapters: 4 - Words: 12,866 - Reviews: 5 - Favs: 8 - Follows: 14 - Updated: 1/31 - Published: 1/18 - Sally-Anne P., Luna L., Albus D., Harry P.
NGE: Screams of Nightmares by Beastrider9 reviews
There are things out there far worse than the Angels. One of them has taken notice of the Events of Tokyo-3 and has machinations and plans of his own. He is Nyarlathotep, the Crawling Chaos.
Crossover - Evangelion & Cthulhu Mythos - Rated: T - English - Horror/Sci-Fi - Chapters: 18 - Words: 94,971 - Reviews: 248 - Favs: 275 - Follows: 293 - Updated: 1/25 - Published: 11/24/2019
Hostis Publicus by Daemon-Sultan
In 1871, a man known only as Rattlesnake began a reign of terror across the American West. Over a decade later he would be known by many more names, the King of Thieves, the Prince of Murderers, the Red Reaper, and in more scholarly circles, Hostis Publicus or public enemy. AN: This is a spinoff of the Bored Outer God series.
Crossover - Cthulhu Mythos & Harry Potter - Rated: M - English - Western/Humor - Chapters: 1 - Words: 5,340 - Favs: 2 - Follows: 3 - Published: 12/25/2021
Of Mythos and Monsters by Mah Lawn reviews
What happens when intentional grimdark crosses with accidental grimdark? This story tries to answer that, in which a ship full of Elder Things encounters a planet full of Monster Girls, and everything will likely go wrong for everyone involved.
Crossover - Cthulhu Mythos & Monster Girl Encyclopedia - Rated: T - English - Adventure/Humor - Chapters: 2 - Words: 8,838 - Reviews: 4 - Favs: 21 - Follows: 29 - Updated: 12/18/2021 - Published: 9/8/2021
Cthulhu VI by Dr. Gairyuki
It's Halloween now on the Boiling Isle. Something was about to be unleashed on the unsuspecting residents and the Boiling Isle itself...
Crossover - Owl House & Cthulhu Mythos - Rated: K+ - English - Humor/Horror - Chapters: 2 - Words: 10,110 - Favs: 3 - Follows: 1 - Updated: 10/31/2021 - Published: 10/22/2021 - [Luz N., Amity B.] Hooty - Complete
Harry Potter and the Bored Outer God by Daemon-Sultan reviews
In which Harry Potter is an avatar of Nyarlathotep. Post-GOF
Crossover - Harry Potter & Cthulhu Mythos - Rated: M - English - Horror/Humor - Chapters: 13 - Words: 60,563 - Reviews: 22 - Favs: 141 - Follows: 144 - Updated: 10/18/2021 - Published: 10/21/2020 - Harry P., Hermione G. - Complete
Maddening Bell by Touhoufanatic reviews
Leaving his village to head to Orario to become a Hero, Bell Cranel witnesses a falling star and goes to investigate only to meet a Goddess quiet unlike any he, or anyone, has ever seen. his fate is now changed, for he has piqued the interest of none other than the Crawling Chaos, of Nyarlathotep, and nothing will be as fate had planned.
Crossover - Cthulhu Mythos & Dungeon ni Deai o Motomeru no wa Machigatte Iru Darou ka - Rated: M - English - Fantasy/Horror - Chapters: 6 - Words: 38,011 - Reviews: 37 - Favs: 305 - Follows: 388 - Updated: 10/15/2021 - Published: 5/11/2021 - Bell C.
XCOM: Mythos Point by Zeroraid reviews
The Ethereal War ended a long time ago, and Humanity took topreparing for the Ethereal's return. Unfortunately as they prepared for one enemy, a second crept out the shadows of the ocean and the cities they defended. It is the years 2177, and the New Earth Government keeps a tight grasp on world after the open warfare between XCOM, sea monster and cultist have taken to the shadows.
Crossover - X-Com & Cthulhu Mythos - Rated: T - English - Sci-Fi/Supernatural - Chapters: 8 - Words: 27,259 - Reviews: 8 - Favs: 10 - Follows: 12 - Updated: 9/25/2021 - Published: 12/24/2020 - OC
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