Izuku: What the hell? Do you feel that?
Asta: Yea, the ground is shaking!
Izuku: Yea.. but that mana. It's strong and it feels familiar!
Asta: Then let's go! The civilians need our help!
Izuku: Yea let's go!
Asta & Izuku start to run towards the noise, once they finally make it Izuku jumps up and kick the wall down as he flys in the speed of light towards Vetto as they both connect their fist together.
Vetto: Ahh...IZUKU! I WAS WONDERING WHEN ONE OF THE STRONGEST MAGE WELL COME!
Finral: IZUKU!! LEAVE! HIS TO STRONG FOR YOU!
Izuku then looks and sees Luck and Magna injured and bleeding.
Vetto: See your friends there? This is what happens when the weak challenge the strong. THEY DIE!
Then light starts to surround Izuku as his sword starts to light up as for his mana start to grow bigger and stronger.
Vetto: ( His mana is getting stronger.)
Izuku: Light Sprirt Magic: Sprirts Dive!
They then see Izuku with his right arm yellow and a yellow wing on his right as well. They then see a two-handed sword on his right hand as well, as a half holo appears on his head.
Izuku: Asta! Remembered what we trained on?!
Asta: You want me to-
Izuku: Yea do it now!
Asta: Alright!
Asta then channels his magic around his body as his left side grows a horn and his arm goes all black.
Asta: Black Asta!
Izuku: ( Not a bad name.) Now, are you ready?!
Vetto: You think your little transformations scare-
Before he can continue he sees Izuku on his left side.
Vetto: ( How did he get there so fast?! )
Izuku then punches Vetto which sends him flying towards the wall. Vetto then gets up and dashes towards Izuku but Asta comes and hits Vetto with his sword, Izuku and Asta then rush towards Vetto as Izuku jumps up points his spirit sword towards Vetto, the sword start to glow yellow as yellow swirls surround the sword. Once the sword was ready large light beam shots out of the sword which hits Vetto, then Asta sends black slashes towards Vetto, which add power to the attack, once they did that Vetto was sent flying out the cave. While that was happening, Noelle, Erza, and Tatumaki had just got there and watched what just unfold in front of their eyes.
Ezra: Wow!
Tatumaki: What just happened?
Astrea: They just beat his ass, that's what just happened.
Finral: Is the fight over?!
Vanessa: Maybe...they did send the beast flying out of here. GREAT JOB BOYS!!!
Izuku: Man...
Asta: We did it!
???: I'LL WILL KILL YOU.
Izuku then looks to see Vetto coming towards them, he then punches them, but Asta and Izuku block it with their sword, but it was not enough to stop the punch, so they got sent flying, then Izuku gets up and sends a Spirit Strom towards Vetto, then Asta flys up and flys towards Vetto, as he does Izuku's attack hit Vetto, but Vetto tried to block the attack but fails as he was pushed back, Vetto looked up and saw Izuku tried to knock him out with the sword but he moves out the way, once he did Asta comes and hit Vetto with his sword which sends him flying. Vetto then counters with a Bear Claw attack towards them but Asta cuts it with his sword, then Izuku sends a Light Wind-haul Cutter towards Vetto, he then sends a Lamp of Avoir towards him as well. Both attacks hit him which inquired him quickly and made him lose an arm. Before he can get his arm back, Izuku and Asta punch Vetto. Vetto then grabs Izuku and throws him toward the wall as for Asta, he slams him on the ground, stepping on him.
Vetto : YOU SEE THIS YOUR FRIENDS ARE-
Izuku then punches Vetto sending him flying. Izuku and Asta then rush towards Vetto, Izuku rush towards the left, and Asta gets the right.
Asta: We won't give up...
Izuku: Not now....
Izuku & Asta: NOT EVER!!
They both hit Vetto which caused him to get knocked out.
Finral: They did it... THEY BEAT HIM!! THE FIGHT IS OVER!!!
Magna: Great...job.....guys.
Tatumaki: I have to admit it, you guys are very strong. ( The Black Bulls can maybe be the...No! No there is no way they can be the strongest!! Right?)
Noelle: Hmmph...great job. ( I WAS SO SCARED!!!!)
Erza: Not bad!! I wish I could've done something tho.
Izuku: Thanks, guys.
They then hear cheers from the outside and see the citizens of the underground were cheering for them.
Citizens 1: They did it!!
Citizen 2: They saved us!!
Citizen 3: Thank you, magic knights!!!
Asta: No Problem!!
Finral: Since when did were you guys able to transform like this?
Izuku: Oh..it something called training!
Tatumaki: No shit Broccoli-kun!
Izuku: YOUR HAIR IS GREEN ASLO!!!
Tatumaki: SO?!!?! YOUR HAIR LOOK MORE LIKE A BROCCOLI!!!
Noelle: AND YOU STOLE MY NICKNAME!!!
Tatumaki: I don't see your name on the nickname.
Noelle: BUT I CALLED HIM THAT FIRST!!!!
Tatumaki: DOES IT LOOK LIKE I CARE!!!
Izuku: Why are they fighting?
Asta: I don't know..but I like what's going on here.
Finral: So what do we do next?
Izuku: Hm? I don't know?
They then feel surging mana coming from Vetto's body and see him waking up.
Finral: I THOUGHT WE BEAT HIM!!!
Izuku: Guys I got an idea! Vanessa ties a string to Asta's feet, then Finral can make portals for Asta to go through so that he can cut him multiple times, or more like teleporting from spot to spot. Then you pull him back as Noelle, Tatumaki, Ezra start to throw an attack at Vetto. Then I finish him off with my finishing move!
Everyone: Alright!
Vanessa then ties a string on Asta's foot then Finral got ready to make a portal.
Vanessa: Ready?
Asta: Let's go!
Finral then makes a portal for Asta to go through.
Vetto: YOU WILL ALL DIE AND SEE HOW IT DISPAIR FEELS LIKE!!!
Then a portal appears next to Vetto, Asta comes through the portal and cuts Vetto with his sword, once he did he teleports above him and slices him, then slices him on both his side. He then continues this multiple times till Vetto hits Asta which sends him flying.
Asta: Now guys!!
Erza: Sword Magic: Origin Flash Barrage!
Erza then made Slashes to slice Vetto.
Tatumaki then uses her Gravity Magic to leave rocks up to hit Vetto with. Noelle uses her new magic spell Sea Dragon Roar and aimed it at Vetto which send him back to the wall.
Everyone: ALRIGHT!! GO IZUKU!!
Izuku then steps up as they see a new sword in his hand
( HIS NEW SWORD!!)
Then light starts to surround Izuku and the sword.
( LIKE THIS)
Izuku: LET'S GO.
Izuku then leaves his sword up above his head and shouted his new move.
Izuku: EXCALIBUR.( @Kishokuhhh I told you I was going to do it! )
( LIKE THAT)
Izuku then swings his sword forward towards Vetto as the large light slash kills Vettos.
Asta: He did it!
Everyone: YAYYYY!!
???: Great job you damn brats.
They then turn to see Yami smiling at Asta & Izuku.
Yami: You guys were kicking ass! Can't be any prouder!!
Finral: YAMI!!! I WAS SO SCARED!!!!
Yami: Oh shut up! You beat him,he's dead!
Everyone then starts to laugh.
TIMESKIP
We see Izuku, Asta and Yami standing in front of Vetto's dead body with their arms all banded up.
Izuku: You know... I feel bad.
Asta: For what?
Izuku: What if we talked to him, instead of just killing him start off the bat killing him.
Asta: Yea...
Yami: Yea, but he was an enemy....so we had to do what we had to do.
Asta: I have these flowers. I thought it would look pretty.
Asta then goes and puts the flowers on top of Vetto's death sheets.
Finral: Hey guys! WHO WOULD HAVE THOUGH GRAY WAS A GIRL??!!!
Izuku: Whose the other one?
Finral: Oh this cutie? She Nero!! ( @Kishokuhhh Another told you as well.)
Izuku & Asta: WHAT?!!! NERO IS A HUMAN/ GIRL??!!!!
Finral: Yea!!
Asta: And why is the 'bird' I meant Nero's cheeks red?
They then look and see her cheeks were red and was looking at Izuku.
Izuku: I don't know, maybe she's sick?
Asta: Hm?
Yami: Anyways let's go home!
Timeskip
We see The Black Bulls, Erza, and Tatumaki waving goodbye to the citizens of the underground world.
Izuku: BYE!!!
Citizens: THANK YOU FOR SAVING OUR HOME!!!
Asta: No Problem!!!
Citizen 5.: Don't forget to visit sometime!
Noelle: We will!
The Black Bull, Tatumaki, Ezra: BYE!!!
The heroes then walk into the portal and go home as the portal close slowly.