Disclaimer: I don't own RWBY nor Highschool DxD. All rights go to their respective owners. I only own Dylan Dragnox and Mávros.
A/N: This is just a little piece of something I've been working on. Isn't a final product and this happens later on in the story. Basically I just wanted to give you guys something for the 1 year anniversary of Rise of Team DARC. I'm going to do my best to see if I can bang out the first few chapters by next month after I finish up pre-writing the Volume 4 arc of RotD.
Dylan glared at the two figures in front of him. He was specifically focused on the White One, called the White Dragon Emperor. The dragon faunus clenched his fists and glared at the man stood up on top of the cliff. "You, Vanishing Dragon, explain yourself." The man in white armor chuckled and uncrossed his arms. "Isn't it obvious? I got you to come after leaving your pathetic excuse of a warrior that you call a wife for dead. So predictable." He said that casually, as if leaving a person near-death was a common thing for him.
"Vali. That was too far. And here I thought you had changed. I knew I shouldn't have left you alone." This time the one in red armor, called the Red Dragon Emperor, spoke. Dylan's clenched his eyes shut and dug his fingernails into his palms, drawing blood. The White Dragon, now known as Vali, shrugged his shoulders. "Shut your mouth, Issei. You were busy with your beloved Rias doing whatever it is you two do. I had to take initiative. We both wanted to challenge the one the people in this world call 'Black Dragon Emperor' and 'Heaven Dragon God'." The Red Dragon, Issei, shook his head. "We agreed to not cause harm here." He tried to reason with Vali, who ignored him and waved him off. "What's done is done. Now, Black Dragon Emperor, will you fight? Or do I have to do some more 'convincing'?"
Dylan's head hung low, hair covering a majority of his face. The 23 year old's tri-colored aura flared up violently, bringing upon the dragon faunus a familiar feeling. "I won't forgive you for what you've done. Either of you." He let out a roar of fury, his scales appearing over his body as his semblance, Dragon Force, activated.
Vali smiled behind the mask of his armor and got into a stance. Issei didn't follow his rival's lead, looking at the dragon faunus curiously. "Hey Vali, do you think that's his Sacred Gear?" The descendant of the original devil king shrugged his shoulders, "Possibly. There was that one devil in the rating game you participated in that turned into a dragon, correct? Maybe it's something similar to that." He theorized, then brought attention back to the furious dragon faunus.
"Draco Armaturam Caelo!" Dylan literally roared out, the Ouranós Ring's gem glowing as Mávros summoned his armor onto his body, the full body armor fitting perfectly with the armor he already wore. "You will suffer my wrath!" Dylan rushed forward, the red-purple pearlescent visor of his armor's mask reflecting the armor the White and Red dragon's wore.
The Black Dragon Emperor punched the White Dragon and Red Dragon Emperors across the face, summoning Lux to his right hand. "This is the end for you. You hurt my wife, my family. For that, you cannot be allowed to live. Divina Irae!"