The pure dragon of order(RWBY x Pokémon x Highschool DxD x Zygarde male reader)

Y/N bio

Age: 16

Looks: However you want yourself to look.

Race: 1/2 human, 1/2 dragon

Master/s: Arceus, Dialga, Palkia, Giratina.

Sacred gear: Zygarde Core.

A sentient core that lays in Y/N's body, waiting to be unleashed whenever he needs it to be

Form it takes on Y/N's body:

A gem that appears on the back of Y/N's right hand.

Abilities:

Transformation:
Y/N can absorb cells and cores into him in order to shift into 3 forms.

10% form

Usually used for small/inexperienced opponents, however, it can take on a high class devil if need be. Is extremely fast, but nothing else that notable, can only use thousand waves in this form.

50% form

Y/N and Zygarde's primary form, this form has an immense amount of power and is often used for high class devils up to other dragons, like the 5 great dragon kings and the Tao Trio(Excluding Tiamat and complete Kyurem.). Can and will be used against Xerneas and Yvetal to control the two. It is also able to take down both the red and white dragon emperors in their juggernaut drives. New moves in this form include Land's Wrath and Thousand Arrows.

Complete(100%) form

Y/N and Zygarde's most powerful form, has unimaginable levels of power and is only used whenever absolutely necessary and when the balance of nature is at risk. The power is more than enough to put the heavenly dragons and primal duo out of commission and is even on par with the Ouroboros dragon and True Red Dragon God. Even Xerneas and Yvetal, the other two members of Zygarde's aura trio, have less power combined together than this form. New moves in this form include Core Enforcer, Order's Blade, and Balance Bringer.

Chant when entering complete form:

I, who shall awaken
Am the dragon that placed the principles of order down upon this world!
I watch out for the "X" and stay wary of the "Y"
I shall become the complete dragon of order.
And it's time you learn the painful truth of what happens when you upset the balance of life and death!

Backstory:

Zygarde was an extremely powerful dragon that lived in his cave secluded in Vale. His main duty was to maintain the balance of life-Xerneas, and death-Yveltal and stop Ddraig and Albion's constant duels. He also made sure the dimensional gap wasn't too full of matter due to Great Red and also prevented it from getting too empty due to Ophis. He also worked with Rayquaza and Kyurem's complete form to keep balance on the planet. When the war between the 3 factions broke out, Zygarde remained neutral and simply let the fighting happen, but as the war progressed and balance tipped towards death, Zygarde finally came out in his complete form and decimated huge amounts of forces from every faction, even killing God and Lucifer, alongside his 3 other kings. The factions then all teamed up and split his power into cells and cores all over the world. Leaving Zygarde's consciousness to only be in one core. That core was then taken by Arceus, where he looked for a host for it. Thousands and thousands of years passed and the creation dragons began to run out of hope as Zygarde's green core turned to a pale blue due to age without a host. That all changed when they came across a certain boy attending Beacon Academy.