|The Writer of Nightmares|
|Allies||The Legion of Evil|
|Universe of origin||Finish the Story|
|Unique and interesting facts||Often writes in first person.|
The Writer of Nightmares is somewhat laid back, being over confident in his powers. He enjoys creating suspense and developing plot, giving the protagonists of the story challenges of high stakes, instead of using his power to win immediately.
The Writer of Nightmares can go beyond the Fourth Wall at will. This gives him the ability to alter the story to his will. Some shown abilities include shapeshifting, creating interdimensional vortexes, summoning monsters, teleportation, and being able to use a Redstone Command Block.
Towards the end of FTS 6, The Writer of Nightmares gains a more physical form, and dons the name "Yoh-Jin". There is little difference between the two forms. The only known difference is that, while The Writer of Nightmares highly vulnerable to the fire from members of the Dreemurr clan, Yoh-Jin was not.
During the final battle, Yoh-Jin absorbs the six human souls, as well as the souls of many other characters, becoming Ultra Yoh-Jin. The battle with this form runs similar to the Omega Flowey fight, in which attacks based on the six human souls appear, the protagonists have to hit the ACT signs, and are healed after a soul stops attacking. Also, both villains let their HP reach zero, completely heal themselves (through different methods), and proceed to insta kill the protagonists (again, through different methods), only to be interrupted by the consumed souls, who defeat their host.
- In FTS 0, Yoh-Jin reappears, though it is unsure as to how he exists in this point of the timeline.
- "Writer of Nightmares" can, ironically, be abbreviated WON.
- During the fight with Ultra You-JIn, the characters sign a parody of Stronger Than You from Steven Universe.
- The karaoke version for the Sans parody of the same song is linked with the lyrics, as opposed to the original version.