The Red exorcist - Blue exorcist x male oc

We will always protect them!

The three demon brothers are standing on top of their cram school looking up at the gate of the underworld

A horde of demons emerge

The three brothers fight them off

Kenji has to burn them all having lost his sword 

A light shines from the gate and beam stares the ground and demons emerge from it

Kenji: dammit what the hell is that

Shura: it's a dimensional tear my guess is he's expanding the gate till it's big enough to swallow Assiah

Kenji: (the devils dream)

Another demon unleashes a blast of fire

Kenji manipulates it too move out of the way

But another fireball is aimed right shiemi and shura

Yukio: WATCH OUT

Rin: SHIEMI

Kenji: SHURA

Then he appears

Arthur: too you villains who would crush innocent flowers such as these i Arthur august angel shall deliver justice

Shura: I took you long enough baldy

Arthur: I can handle this one just sit back and watch the fireworks

Kenji and Rin: DON'T TELL ME WHAT TO DO!

Arthur shreds through a ton of them

With Zodiac slash

Rin uses his sword to burn them away

Kenji compresses his crimson fire to shred through them

But there are still way too many

Yukio: separate hit won't work we need to time we have to time our attacks

Shura: yukio's right about that we have to work as a team or we'll never break through protective wall of steel

Rin: sure your up for it that goes for you too Kenji

Shura: worry about yourself kid

Kenji: what she said I may be weak but I can still kick your ass

Arthur: i me be thought I join forces with the sons of Satan how revolting

Shura: SNAKE FANG!

She sends out a flying slash attack slicing through many demons

Arthur: ZODIAC SLASH

He tears through many demons

Kenji then uses Arthur as a spring board

Arthur: what the

Kenji: thanks for the lift baldly now why don't you watch some fireworks

And condenses his flames into one point

Kenji: crimson.....WRATH!

The compressed flames explode burning away many demons

Kenji: alright your turn rin

Kenji and then allows rin to step on his foot and Kenji pushes off sending rin flying into the sky for him to burn away many more demons

Kenji flips around and emits his crimson flames form his feet and he flies right up to join his brother

With flames of red and blue they blast at the gate

And fall

Shura: We did it!