So... I don't know what to really write, so I will just advertise myself.
I write fanfictions in Webnovel under the account of General_Paragon, or in Fanfiction.net as The_4uditor and I work only on Original Characters(OC), if you are interested in crossovers or fanfictions in general on Monster Girl Quest, I already made two and still doing a third:
1) The Misadventures of the Espada: A crossover between Bleach and Monster Girl Quest, with the main character being an OC that is classified as the Espada 0, taking Yammy Llargo's place. However, I suggest this only if you really are bored, because this is my first MGQ fanfiction, so it can appear as trash in your eyes.
2) Nine Tailed System: A fanfiction on Monster Girl Quest with Naruto elements, the main character is another OC belonging to a trilogy. (I suggest reading Hail the Ant King, a Rosario+Vampire and Hunter x Hunter crossover if you want to understand more)The main character has a particular motto of doing literally everything he said, no matter what, and has also a half-assed system that permits him to become a pseudo-jinchuriki.
3) Alter Ego System: Another fanfiction on Monster Girl Quest with a proper system that works with gacha that features a main character whose system was split into 4 fragments. He holds one while the three other fragments took life and used the looks of the main character to interact with the world. This will continue in Monster Girl Quest: Paradox at halfway from the story, and there will be different twists here and there to assure nothing stays monotone.