The Knight of Ruin(DxD)

Samuel Liddell MacGregor Mathers, one of the greatest human mages to have ever been born even before becoming a Devil. It took Sirzechs both of his Bishop pieces to reincarnate Mathers. When he was human he founded The Magician organization The Golden Dawn which he was still in contact with. 

The man had lived for more than 150 years and had become even stronger throughout that time when time held no meaning for him as a Devil. He wore a crimson robe with a distinguished design and a permanent aura of magical suppression radiated from him.

With a wave of his hand, Romonus' room was covered in multiple wards so no one would hear their conversation. 

"Alright Romonus, explain why you want to kill Diodora. Even if you don't convince me your secret will be safe." 

Romonus sat down in his favorite chair as he explained. 

"Master, it goes like this. I can't see the future, I receive glimpses of prophecy in my dreams. I have no control over them, but from what I have seen they can be changed."

MacGregor pondered on what he had been told. 

"Interesting. Got some examples?"

Romonu nodded. 

"Yes. Rias was involved in many events I keep picturing which all take place 7 years from now. I already knew of her engagement to Riser, but oddly enough the version of events I keep seeing don't involve me. Like I don't exist. 

If I did not exist Rias would continue to waste her time and end up having to challenge Riser to a Rating Game which she would be expected to lose. But my existence caused this to change." 

MacGregor's closed his eyes as he pondered on the words he heard. 

"Very curious. So, in these visions, you don't exist?" 

MacGregor extended his hand out and a grimoire appeared in his hands. He flipped through it at incredible speeds before he put it away. 

"I get what you mean. So, Diodora causes trouble in the future?" 

"Yes. Diodora betrays Devil Society by joining a group called the Khaos Brigade led by Rizevim. Rizevim will manipulate Ophis The Dragon God of Infinity as you know she is rather simple. Shalba Beelzebub, Crusery Asmodeus, and Katerea Leviathan will all join this group." 

McGregor sighed. 

"And you didn't think it smart to say so beforehand? We can prevent this by leading an assault beforehand."

Romonus shook his head. 

"I planned to take the Hearts of Shalba, Crusery, and Katerea and if we move beforehand I will miss my chance. I wanted at least 5 more years of training before I was going to bring this up. I only told you because I know you well Master."

McGregor began to laugh. 

"You greedy little guy, you want the bloodlines of the original Satans. This sounds fun and chaotic. But Chaos is fun and so much can be learned. Your secret is safe with me. Let's kill is Diodora. Show me your spell." 

Romonus smiled as he pulled out a journal from his Spatial Ring and flipped it open to the page of the spell. He handed the journal over to his Mentor who began to flip through the spell. 

"Damn. You want to call on The Harvestor of all things, wicked. As for the spell itself, it is a mix of Voodoo, Black Magic, White Magic, Summoning Magic, Norse, Fairy, and Demonic Magic. You have done a good job with this, but let me just do this.

You do not want to get caught by Ajuka, but The Harvestor is unique. Creepy fellow."

From thin air McGregor brought out a pen and began to change up the ritual lines, added some of his expertise, and added in ways to hide who cast the spell. It took him all of a minute to be finished with the edits. 

"Here you are. Now, you will be much safer and harder to track. Consider it a gift."

When Romonus saw the improved Ritual he smiled. 

"Will I ever compare to you, Master?" 

McGregor laughed as he ruffled Romonus' hair.

"If you give up the path of the Knight and Rook, and focus exclusively on Magic of course. If you decide to keep on the current path you have of focusing on all three, then no." 

Romonus did not believe that. 

"I have thousands of years Master. I will become the first Devil to ascend to Godhood as even my brother has not achieved that. How can I allow myself to follow a single path when three are laid out in front of me." 

McGregor stared at Romonus for a few moments before he broke out laughing. He keeled over and held his stomach as he continued to laugh. 

"HAHAHAHAHAH! YOU CERTAINLY HAVE A GOAL KID! Fuck it, come on. Let's do some Dark Magic and get you a heart. Fresh of course." 

Romonus got up and looked over the ritual circle that his teacher edited for him. Once he memorized it, he pulled out his sword from his Spatial Ring. It was not his Demon Sword, but the one he had forged years ago as he did not want to use it yet. 

He pulled the sword from its sheath and cut open his wrist. Mcgregor simply watched as he turned his wrist over and began to spill his blood onto the ground. Romonus focused on his Demonic Energy as the blood spilling on the ground began to move into lines, symbols, and shapes of multiple magic systems. 

His teacher observed his work as he checked for mistakes, but Romonus had been learning under the mage for 6 years. He would not make a mistake like that as he knew the risks associated with magic. 

When he was finished, he felt he had lost over half of his blood, but in the ground, a large 6-foot by 6-foot blood Ritual Circle had been formed. It was the most intricate thing he had formed and he was already feeling light-headed. 

He staggered over to his alchemy table and grabbed a Red Potion which he chugged down. Macgregor did not offer him any hold and just watched as Romonus closed his eyes and began to circulate his Demonic Energy in his body. 

In a few moments, his pale face recovered its color and his lightheadedness went away. When he opened his eyes they were glowing bright purple as his potion flowed through his system. 

"What was that?" 

"A Blood Potion. Made for speeding up the recovery of blood. I made it from Blood Shrooms, Grasping Devil Vine Flowers, and Crimson Moss."

"Does it have any downsides?" 

He nodded. 

"Drinking it when you don't need it will make you die of Polycythemia vera. Blood thickening, but when needed it can be a lifesaver."

Romonus kneeled opened up the cabinat on which his alchemy table was and pulled out a green potion which he drank. He once again focused on the potion and used the healing herbs to heal himself. 

Once he was done he continued to circulate his Demonic Energy to make sure nothing was wrong. This whole thing took him about 10 minutes, but his teacher did not rush him. When he felt he was ready, he stood up and walked over to the magic circle. 

"Alright, what do you have to mark Diodora as the target?" 

Romonus pulled out the blue hair he had taken from Diodora and showed it to his teacher. MacGregor nodded as that would work excellently. 

"We can begin. Give me a few moments." 

MacGregor from his Spatial Ring pulled out 9 stones of pure refined Souls. He placed them in each circle in the 9 corners. In the center, they placed Diodora's hair. He turned to Romonus with a serious expression. 

"You do it. This is your spell I just fixed it for you. Latin will work just fine, just remember, The Harvestor can reject your offer so be careful."

Romonus nodded as he placed his sword back in its sheath before he kneeled in front of the Magic Circle. He placed a hand in front of it before he began to send his Demonic Energy into the circle. 

He took a deep breath as he began to chant and the circle began to glow a bloody red as he began to chant in Latin. 

"Invoco maledictionem Harvestri. Ut pretium sanguinis solvo, Harvestrum voco pro cruento commercio. Ut invoco cruentum opus, Metet cruentum praemium Pro reproborum Cor." 

'I call upon the Harvester's Curse. As I pay the price of blood, I call on the Harvester for a bloody exchange. As I call on his bloody work he shall reap his bloody reward for The heart of the damned.'

He repeated the chant 9 times and each time each Soul Stone burst apart and flowed into the center surrounding the hair that belonged to Diodora. MacGregor opened his journal and began to note down what he needed to improve, but nothing would go wrong with him here. 

With each repetition, the more Demonic Energy he was losing, but when he finished the 9th chant a huge amount of Soul and Demonic Energy surged around the blue hair. Romonus backed away as the Mana and Demonic energy began to rise into the air as they consolidated into a figure. 

A gaunt hooded figure formed in the Magic Circle. The Harvestor was a magical entity formed and summoned from the Spirit Realm, but some believed him to be the Grim Reaper. Romonus did not know if that was true or false, but MacGregor knew more. He just wouldn't tell him. 

(Image here)

The Harvestor looked down at Romonus who kneeled with an extended open palm. The figure stared at Romonus for a few moments before he nodded, turned around, and vanished. MacGregor grinned. 

"He accepted." 

Romonus stood up and looked over to his teacher. 

"You mean to tell me he could refuse?" 

MacGregor nodded. 

"Yes. He is whimsical and it seems he took a liking to you. I once called on him and he rejected me. I wonder why he listened to you." 

Romonus was now slightly worried. 

"He won't take years off my life will he?"

"No. Equivalent exchange, those 9 souls were the price we paid and it was enough to manifest him for a time. He will get you your heart. We just have to wait for him to finish. I wouldn't wish The Harvestor on my worst enemy. Oh wait, I tried. HAHAHAHA?"

Romonus sat down in his chair and waited for The Harvestor to do his bloody work.

---

Diodora was currently quite pissed after what Romonus told him. He had worked hard to keep his fetish secret as if his family found out what he was doing they would punish him. If the Church or Heaven found out they would hunt him down and start another war. 

Currently, he was venting his rage on his Queen. He was in no way being gentle as the former Holy Maiden was forced onto the bed with a pained look on her face. 

"FUCKING BASTARD! WHO DOES HE THINK HE IS!" 

"M-master, p-" 

"SHUT UP!" 

Diodora reached down and wrapped his arms around her throat. 

"Who told you to talk? You don't talk. This mouth is to suck me off and nothing more. Got that?"

She did not say anything as her eyes began to roll back into her skull, but as Diodora was about to finish inside her he felt a cold chill. 

'What?' 

His luxurious room went from his private abode to a cold terrifying place. He got off his queen as he waved his hand to form clothes around himself. 

"What is happening?" 

He turned to his peerage which he had been abusing since he got back. 

"YOU! WAKE UP! PROTECT ME!" 

Sadly they were out as he had knocked them out from the abuse. Just as Diodora raised his arm to punish them he suddenly felt something new. He looked at where his hand would be and instead found a stump. 

A quickly rotting stump which made him panic. 

"AHHHHHHHHH! MY HAND!" 

He fell to the ground as he rolled around in pain. When he looked up he noticed The Harvestor looking down on him. In his hands, he held a black scythe at the end of a chain, and on the floor was his rotting hand. 

"YOU BASTARD!" 

Diodora raised his remaining hand and formed a magic circle from which he was going to attack, but The Harvestor swung again and cleaved his remaining hand. 

"AHHHHHHHH! MY HANDS! NO! STAY AWAY!" 

He backed away before raising his rotting arms and forming a massive green barrier as he called upon his barrier magic. He began to madly laugh as he continued to bleed rotting blood. 

"EVEN A ULTIMATE CLASS DEVIL WILL TAKE TIME TO BREAK THROUGH THIS! I am DIODORA! RELATED TO THE GREAT BEELZEBUB! YOU WILL DIE!" 

Unimpressed the Harvestor floated toward the barrier before he lightly tapped it with a bony finger. Instantly, the green barrier collapsed under the surge of Necrotic energy. 

"W-w-what?" 

The Harvestor floated toward him and leaned in close. When Diodora looked into the hood he saw his own rotting face. He gasped as a dark bony hand was shoved into his chest. He reached up with his stumps to grab The Harvester's arm, but he was undisturbed. 

Taking a sick joy in this, he slowly pulled out the still-beating heart of Diodora. Unlike everything else, the organ did not rot in his hold. The Harvestor looked at the heart in his hand before he burst into darkness. 

When his peerage would wake up, they would only find a pile of ash confirmed to be Diodora. In the morning the whole Astaroth clan would be shocked at the death of their heir. Ajuka would be informed who would begin to search for answers.

Ending Diodora early had a great domino effect on Fate which Romonus' boss reveled in. Romonus kept his word to cause as much of a mess as he could and he was delivering.