Two unknowable entities faced each other. The space they occupied was filled with nothingness; simply an unending void. Despite its emptiness, the void was colored, half in white and half in black.
"Hey, you. Other one...uhhh Luz" the black void called out.
For a moment the call went unanswered, but then the white void replied, "What is it Grimm?"
There was a sense of annoyance being projected by the white void, called Luz. This tonality brought joy to Grimm's 'face' and if he actually had one, it would be taken over by a toothy grin.
"How much longer you going to hold back? I know you've been getting in the way of the kid's ability to use his mark." Grim questioned.
"It is for his own good. As long as I can't make a move, neither can you."
"Oh, come on, you know I followed the rules. You let him borrow power first and collected your toll. What was so wrong in me doing the same? Fair is fair, right? That's what we agreed on after all." He whined.
It was true. When they felt a window into their space open for the first time in a millennium, they both felt elated at finally being able to break this stalemate between them. Unfortunately, the window was small, weak, and unable to really accept their power.
Over time this window grew bigger, stronger, more stable, until one day they were able to cast their voices through it. On the other side was a boy, young and weak, fighting for his right to survive. Grimm of course saw an opportunity, though it was risky. As per the rules they set, they could only move in turns, at least until the boy could call on them on his own.
Grimm and Luz played a waiting game to see who would be the first to make the opening move. The second one to make a play had the advantage of responding to the opening gambit, so Grimm waited and waited.
"At least until he breaks through on his own that is."
"What?"
"Oh, come on! Don't tell me you didn't realize it? If he's filled with enough anger...enough hatred...I can just slip right on by your little blockage."
"The same could be said if he has a strong enough desire to save someone...to protect them." Luz countered.
Grimm smiled once again. "Sure, that is true...however...what do you think is more likely in this world? He's a boy marked by 'demons' and is the son of a human and a beastman...he's a commoner in service to a noble. A weak child stuck in the Novice Rank...do you really think that he won't be struck down by the negativity and cruelty of the world first?"
"You don't know for sure, Grimm."
"Of course...but it's a risky gamble you are playing, old friend. I do enjoy seeing you play it though...time will tell. Oh hey, did you notice?"
"Yes."
"I wonder how they are doing that. Watching...so interesting! I don't know who they are...where they are...but to think, someone can peer in here...can they hear us...do they fear us? Hey Luz...want to make another bet?"
Once again, Grimm was met with silence. Luz's power and concentration at the moment were split between holding him back and blocking his path to the window into the earthen plane. The realization that someone else was able to look into their void made him wonder if there was another exit to use, but he discarded the thought.
After all, even if there was a second window, he probably would not want to use it. This one seemed so fun and the game he was playing with his counterpart was just oh, so enjoyable.