The Betrayed Beast (MHA x Black Clover x Demon Slayer)

Chapter Twenty-One: Where it All Ends (Finale)

"Y-You saw on your dream?" Iida asked. Asta's magic now surges out of his body and his devil is slowly getting disintegrated by it. He himself wouldn't want to stop Asta anymore as the boy who was known to be a victim of humiliation and bullying now rages himself out.

"Leon! Is that how your mission ends as a devil?! Even if you are an abominable force from the underworld, that doesn't mean you won't do good things for us all! Please help us to stop Asta from destroying everything!" Gyaku yelled.

"I... I... I... can't..." Leon uttered.

"What do you mean you can't?! You told us everything you know that will help us succeed till the end! And now you're giving up already because your job to keep his dangerous magic has failed?! Do something!" Gyaku yelled.

"Hahaha! Look at these unworthy friends of yours, Asta. Like what I've said, you gain nothing if you live with these people. Join forces with me and we'll rule this world for good!" Roth invited.

"Even if... even if my devil betrayed me by lying about my magic... that doesn't mean I really hate him from the bottom of my heart!" Asta uttered as he tries to control the destruction of magic overflowing in his body.

"Asta..." Yuno uttered.

"Huh?! You really don't get it, Asta?! These people brought you nothing but despair and foolishness! I heard that most of the people here want you dead because you were the cause of the elves attacking this kingdom! And yet, you still want to protect them?!" Roth angrily asked.

"And where were you when I lived without magic and slept in the same house with people whom I don't know, that their heads with you?! Where we're you?!" Asta angrily asked.

"Forgive me for being not with you, Asta, ever since you were born. I was really busy preparing to unleash the underworld here in this world and open the seven gates underneath of it. The reason why I let you and Yuno ran away is to get stronger and join forces with me in the future." Roth said.

"With you? Who told you we will be working under you?!" Yuno angrily asked.

"Father... If you really are my father, please... stop and surrender already. Even if Leon betrayed me, he is the one who took care of me and I thought of like a big brother!" Asta said with a smile. Leon smiled at his host and gets pumped up.

"You really don't understand, Asta. Satan, eliminate Leon now!" Roth yelled.

"Sa uoy hsiw!" Satan replied. The devil didn't notice where Leon is and he felt someone hanging into his neck as Leon chokes him.

"Who told you devils can't fool their fellow ones?" Leon said with a smirk.

"Everyone! Even our magic has no damage, distract Roth, and make an opening for Asta!" Gyaku yelled.

"Follow the orders of the red mohawk guy!" Fuegoleon added.

"On my lead!" Gyaku yelled and now calls for the other magic knights to follow him.

"Your devil is... still fighting...? I guess I have no choice but to bring this out then." Roth said. A black hole appeared under him and a diabolical looking rifle with a skull muzzle on it appeared.

"What the?!" Asta grunted.

"Dark World Magic, Dark Cannibal Cannon!" Roth exclaimed.

"Kid! That cannon is a devil-destroying weapon! If you get hit by that, we'll be dead in an instant. It quickly devours your and my body as it hits us!" Leon yelled.

"Destruction Magic--" Asta stopped as his heart stopped beating and purple mist starts to cover it.

"Since you haven't used that magic since birth, it will now be contractual magic, my son. Once you use too much destruction magic, your heart and soul will be destroyed forever." Roth said.