Third Person POV
"Been a while brother."
Rizevim said that with an arrogant tone in his voice while he was walking towards Cain. When he crossed Zeaira he stopped for a moment and looked at her
"You are the one Cain protected right? Let's how you get by after I kill him."
Hearing that everyone is shocked. Nobody thought that Rizevim would straight up say that he will kill his brother.
"What about the contract?" Cain said
Rizevim laughed and replied "Contacts are meaningless to super devils. Only special things can bind us."
Hearing that Cain laughed and said
"Super devil? Who You? Don't make me laugh. Your presence is nowhere near Zeaira or Ajuka. They will whoop your ass. And me, my slap will send you to the juraasic era."
"I dont know what the hell 'Jurrasic era' means but I will have your head today."
After that both Cain and Rizevim came face to face and stared at each other whole letting their aura run rampant. Cain's hand were still in his pocket, while Rizevim had a ferocious look on his face.
In the middle of the wild stare down Cain spoke to Rizevim in a low voice which can be heard only by the both of them
"Did you like the holy coins, dear Rizz?"
Hearing that Rizevim made a furious face, a contrast to his ferocious face just now but before he could speak something Cain kicked him in the stomach.
He was thrown backwards even when his legs were rooted in the ground. Multiple sonic booms were realesed by that kick. Showing that Cain had just kicked someone with a speed many times that of sound.
And after that he went to attack Rizevim not giving him any leeway.
Zeaira seeing that went near her father and said
"Father, now you will know why Cain said that. Because even I would say that Cain is the strongest devil."
...
Rizevim knew that he was not a match for Cain but for him to say that even those lowly devils are stronger than him truly pissed him off. But he knew he couldn't give in to his anger and duke it out with Cain. As he knew in a close combat fight Cain would rip him apart like a hungry man woukd rip apart a piece of bread.
So he started casting magic to enhance his defence and reaction speed. But even then he was being forced back.
'Looks like he still has some plans running in the back of his mind. Well he is going to die today so no worries.'
Cain was not taking this fight seriously as he has learnt all the magic in the Lucifer castle library so he will not be surprised this time.
Not to mention that Cain unlike Zeaira and Ajuka who overshadow Rizevim, he dwarfs him in pretty much anything.
'Let's see what you gonna do my brother.'
'My sacred gear cancellor ability is useless against Cain and his darklight nullifies my magic and to top it off he is better at hand to hand combat. And he hasn't started using his scythe. Looks like I will need to play dirty here.'
...
The air around the two Lucifer brothers was crackling with untold intensity. Rizevim was trying his very best to stay far away from Cain least he gets blitzed.
"Till when are you going to run my dear brother?"
Cain mocked Rizevim, but Rizevim stayed calm while simultaneously using magic strong enough to kill ultimate class devils.
"Just wait Cain soon you will know my plan."
Rizevim was secretly gathering his magical energy to unleash a big attack on Cain. Thus he was buying time.
But even buying a little time was proving to be ridiculously hard when Cain was using darklight chains and seemingly covering the entire battlefield with its range.
The battlefield was continously changing between the ground and sky. The other devils were very surprised as they didn't knew both the Lucifer brother were this strong.
The sound of Cain cutting magic with his scythe and the bombardment of magic spells by Rizevim was creating a symphony of Arcane and steel.
Every time Cain cold steel of scythe would near Rizevim he would teleport, resetting the battle to the start. Most devils were thinking that the two brothers are equally strong but only the stronger devils were able to tell.
Cain was toying around with Rizevim. While it looked like it, Cain was only using his scythe as a normal scythe and darklight chains only nothing grand, almost as if he didn't consider Rizevim worthy.
Suddenly Rizevin laughed like a joker
"Uhyahyahyahyahya, finally my magic is ready."
'The fuck is that laugh.'
And saying that Rizevim revealed sixteen 10 meter bullets made up of pure demonic energy and launched it at Cain.
Those bullets contained enough energy to destroy a country showing that he wasn't called a super devil for joke. But Cain didn't dodge those bullets and swung his scythe after covering it with liquid darklight simply cutting them even before the bullets reached him.
"Did you really think that will do something, let me show how it is done."
Saying that Cain raised his hands and a single 25 meter darklight spear appeared in the purple sky of the underworld illuminating it and started falling downwards.
Seeing that every devil there was shocked. But Rizevim didn't lose hope and created thousands of magic circles around him. Each of different magic spell showing that his magic casting wants inferior to the Diabolism Thousand Dragon, Aži Dahāka.
The clash between the magic and darklight rattled the entire space around the battlefield.
Rizevim had to give it his all just to stop one, seeing that Cain said.
"Very nice. But what about the remaing ones in the sky?"
Hearing that Rizvim looked up in the sky to find 25 Darklight spears each as big and destructive as the first one piercing the clouds and revealing themselves falling down towards the battlefield.
Seeing that Rizevim only made a bitter smile and muttered something and started to cast numerous magic spells on himself.
While the other devils watching it lost all the thoughts the had. Only one thing going on in their mind
'How can someone resist against that?'
Cain literally used the max power he can use with darklight without going super devil. And it more than enough to destroy multiple countries at once.
Seeing that all the devil lords and the future satan created a huge barrier in an attempt to stop the damage caused by Cain.
Cain only used a move like this because he knew Ajuka and Zeaira have big enough reserves to create a barrier which can withstand his blows.
The attack of Cain was visible to the entire underworld. Many devils thought that the great war had been restarted and the angels were attacking.
The falling of those spears was like armageddon. The moment the spears touched the ground, a blast bigger than any blasts in all of biblical history. The only reason the devil society existed was because of the barrier erected by Ajuka using his kankara formula and Zeaira's massive demonic energy reserves.
The shockwave from the attack was devastating. Many weak devils fell even after the barrier absorbed most of it.
Cain was standing even after all of that while Rizevim was no where to be seen. But after the smoke cleared the devils saw Rizevim on his knees while Cain was standing in front of him with his hands inside his pockets.
Rizevim's magic spells had atleast protected him somewhat. But his armour had completely been broken and he was bleeding from wounds which were spread all over his body.
Cain was surprised seeing that his brother was like this l, even though Rizevim was also a super devil but then it struck Cain. And he spoke going near his brother
"Oh looks you cant transform like me or Zeaira neither do you have a special magic like Ajuka. Let me guess you haven't truly understood what your power is, right?"
Cain was right Rizevim wasn't a true super devil currently he didn't focus much on that for unknown reasons. But even though he was blatantly at a disadvantage Rizevim said
"Indeed, Cain but you shouldn't have gotten this close."
Hearing that Cain sensed something or more precisely someone coming outside from Rizevim's shadow and attacking him with a powerful attack. Cain brought his hand to stop it but the attack launched him kilometers away and embedded him inside a mountain.
Seeing that everyone was shocked and the figure was revealed to be Euclid who was panting hard.
"Your plan worked my lord. Even if he is strong he can't remain unscathed from an attack from a satan class devil with full power."
But soon after every devil started to look at the mountain range in which Cain was blasted. Every devil was having an uncanny feeling.
...
Cain came out from the hole in which he was in and removed the destroyed clothes. But he didn't even bleed the only thing was that he was propelled far away.
After all he blocked that attack and Euclid isn't that strong.
"Even so, I need to tell them why I am the Lucifer."
Saying show Cain swung his scythe very slowly but the power in that was astronomical. The result was that te entire mountain was destroyed and the shockwave reached the other devils.
This time again there was a bitter smile on the face of Rizevim. He warned Euclid
"Move away-"
But before Euclid could comprehend he was already thrown miles away from a single punch by Cain.
Cain had instantly reached him. No devil present was able to see it happen. One moment Cain was near the ruined mountain and the next time he was at his previous position with Euclid flying and creating sonic booms.
"Time to get serious, huh my brother."
Even Zeaira was surprised as currently Cain was releasing energy above that of a Satan class, even though he hadn't transformed. This was possible because he had mastered his super devil form.
"Let's end this Rizevim."
Both the brothers knew that this would be the end of one. And everyone knew who it is. But even so a injured tiger is more dangerous. This time Cain had no intention of giving his brother a chance to escape. He has decided that this fight ends here.
Cain rushed in for a close combat fight with Darklight chains and his scythe assisting him. Now that Cain was going in with his top power and not just using it for AOE attacks Rizevim was really struggling in the fight.
Every exchange would result in a cut or a punch for Rizevim. Only thanks to his defense spells he was able to even continue fighting but even then Cain was gradually cornering him.
And it seems like Euclid was out for good since he hasn't intervened till now. Now that all of Rizevim's tricks were useless since Cain was fighting seriously he also started fighting like his life depended on it.
But alas a normal devil could never hope to defeat a super devil. In the end Rizevim again fell on his knees, bathed in blood, panting and accepting his fate.
Cain raised his scythe and coated it with liquid darklight and in the midst of he remembered something Nyx had told him
Flashback no jutsu
"If you chant about concepts and abstracts things like fate and destiny the will from your words will strengthen your attack. This is the reason why many gods have such poems for themselves."
Comeback time
Remembering that Cain started to say
"Scythe of death, darklight's embrace,
Unleash the tempest, the void to trace.
In the dance of echoes, let chaos surge,
The final requiem, the eternal dirge."
As the words were uttered a huge scythe formed in the sky in purple color which was gradually covered by darklight and started shining brightly.
"Blight the heavens, shatter the veil,
With each swing, let dimensions quail.
I am the bringer of fate untold,
In this dark symphony, your tale is foretold."
With that two enormous hands appeared and held the scythe and swung it down on top of Rizevim's head cutting him from the top to bottom in to two equal halves which vaporized as soon as they separated.
After everything was settled down, only Cain with his scythe could be seen on the battlefield with no sign of his brother.
'Nyx wasn't wrong. My attack was atleast twice as strong as it would be normally.'
Cain looked towards Zekram nd spoke clear and loud
"Zekram you may give the seat of Beezelebub, Leviathan and Asmodeus to any one but the Lucifer seat is mine because. I am the Lucifer!"
With that line one satan was decided and the devil civil war ended for good. Now only rebuilding hell and taking it to new heights remain.
AN:- Whew finally the arc ended. Now the epilogue and we enter the kingdom building and peerage arc. A little late bcoz I was busy shopping. Point out any error or typos.