User blog comment:Kogath/Monster Hunter XX Discussion/@comment-26532315-20161027164501/@comment-26995086-20161028144357

Okey here is the source for the "red diablos with black horns" seems like i missunderstood forgot and added stuff there or it was in the quest description in MHFU idk :)

Monster Hunter illustration book vol.1 page 58 a picture is shown of 2 diablos fighting wich one having a redish color and darker horns and the other one just lost a horn (i presume the demon king).

The text says: "The Diablos i saw was almost twice the size of the other male of its own kind that had mistakenly wandered into the behemoth´s terretory. As the giant diablos circeled its offender, its red carapace shook with rage. I can still recall how small the lost diablos looked in comparsion to this mighty specimen. No doubt the red giant was as a king among its kind."