The work of the dark type gym leader/Leader of team Nightmare.
Ghan: Dark-type gym leader. Runs through regions with new Pokemon to face trainers and rack up wins and open a variety of pokemon. He lived in the woods with his mother, playing with dark-types everyday and again. This ended up in specific two sticking with him. Shinx, and Bisharp. "Darkness can be null. Empty, nothing, no one. Someone in such darkness would need a bit of light... I can be both the dark and light for ya!"
Rio: Leader of team Nightmare. He was a joyful young trainer who traveled Sinnoh with his Luxray, Don. One day, team Galactic tried to steal him and caused an avalanche, sending his favorite Pokemon so far down that it's 6ft under. From then on, he swore to bring down all evil teams. Starting with Team Galactic. "Dreams are fleeting, like how conquering if futile. Nightmares are endless, like I am abyssmal. You will fall in an endless void. Strangling to get out. You WILL feel pain, like Don.."