I'll use Mira, and see how she stacks up.
Name: Mira
Gender: Female
Typing: Fairy/Normal
Moveset: Dragon's Rage (Special attack, 110 dmg, Dragon type) Crystal Storm (Physical attack, 100 dmg, Ground type) Starblast (Special attack, 100 dmg, Fairy type) Diamond Dance (Special, Increases Special/Pysical attack by 2x for 3 turns, Normal type)
Z Move: *Needs and Mirium z* Mythic Starstorm Rage (Special attack, 250 dmg, Fairy type)
Ability: Shining armor (Hidden ability when given Mirium z,cuts dmg of super effective moves by 2x, making moves effective to Fairy/Normal neutral.)
Stats: Hp 106 Atk 150 Def 90 Sp.atk 194 Sp.def 120 Spe 140
Iv Spread: 4 Def/ 252 Sp. Atk / 252 Spe
Nature: Brave- +Sp.atk -spe

It’s late but accepted.
Reterna appeared!

{Mira hopped to the side and glared at the mysterious creature} "Who are you?"

Without warning, it shot off a cross poison.

{Mira was hit in the tail, and she gave an angry roar that rivaled even a lions. She turned to him and attacked with Dragons Rage.}

((Dragon rage always does 40 damage.)) it poisons it with toxic and then venoshock.

((Oh, I made a fanmade one *the one that has 110 dmg*, I didn't realize they had the same name until it was to late.)) {Mira used Diamond Dance, increaseing her powers.}

It then hits with another venoshock. The power doubles to 176 when the target is poisoned and doubled by super effective, plus stab which is 422.4 base power.

((Woah that's a lotta dmg I think I'll rename it Raging Drake)) {Mira fell to the floor.}

((If you think that’s a lot look at this))

OOh.

And why not choose the name dragon rend

Alright, lets go. I'll use the Kiku triplets as usual, unless you want me to use a different OC?

now at low health, it uses dragon pulse.

It was about to hit Ao, but Murasaki jumped in front of him to shield him. "Gr....moonblast!" "Icicle crash!" "Stone edge!"

It was defeated...

or.

WAS IT?

Okay. Kiku triplets vs reterna.

RETURNA appeared!

Akaikiku looked over at Returna. "I'll rip out your soul."

((Also, is it funny i passed elite, ender.knight, and dralignment in points?))
“I don’t have one.”
((Neither do I))

((Yee. I guess that makes you a good memer, eh?))

Aka shrugged, then I'l just tear you apart to compensate.

(mood.)

Reterna used dynamax cannon!

Suddenly, a wall of ice appeared, then shattered when it was hit. It was Aoikiku, standing next to his brother. "Jeez, Aka....you need to stop getting us into fights...." he sighed, making Aka shrug, "Eh, who cares?!" he laughed, before swinging his knife while it was laced with fire at Reterna.

“Fire is weak against dragon. Didn’t you learn? cross poison!”

Aka groaned, "But arent you made of steel? If not, then your appearance is misleading!" he said, before lacing the knife with ice. He looking over at Ao, "Well?! Do it!" he said, making Ao nod, "Ah, right! Blizzard!"

It countered with fire blast.

Ao started pouting, "No fair..." he said, making Murasaki appear. "Oh, Ao, I agree, but nothing in life....or death ever is fair..." he said, before looking at Reterna. "Hm....whats your type? Pure dragon?" he asked, before hitting his staff on the ground and using rock slide on Returna. Aka hit him with a earthquake and Ao hit him with icicle crash.

((The Kiku triplets types:
Ao: Water/Ice and Ghost
Murasaki: Flying/Electric and Ghost
Aka: Fire/Ground/Rock and Ghost

“Who are you? Explain now.”

“Get ready for a FIGHT! DYNAMAX CANNON!”

Jiren:*standing still* *take no damage*

“Fairy types. Ah. CROSS POISON!”

Jiren:*Tremendous Willpower*

Jiren:*Telekinesis

“Dynamax cannon!”