Cyan streaks darted across the battlefield as a white blur clashed with it. A blade of steel met with claws of ice as a visored hood met the glare of blue. Hopping away from each other, a magickal circle formed under the feet of the claw wielder as wings formed behind the swordswoman. 

"They're getting faster," Timothy, in his skeletal form, said as clashes of blade and claw echoed on the battlefield. 

"Issei's mastery of interdimensional hopping is second to none, even better than Kiana's innate connection to the void," Mei noted, her beautiful purple eyes tracking the duo with ease. 

"Indeed, his mastery of the Atealan art of Riftwalking has made master Issei quite formidable," Timothy said as he raised a shield to block some shards from a dodged overhead blow from Kiana Kaslana. 

"The Song of the Stars combined with Soul blinking," Mei whispered as she disappeared in a purple flash. 

A katana sang in the air before it clashed with a gauntlet connected with a claw of ice as a shield formed behind the young claw wielder, blocking a greatsword blow from the Dragonlord of the Blazing Void. Without missing a beat and in less than a second, the figure disappeared in a cyan streak, leaving chains of ice-blue wrapped around the Dragonlord of Storms. 

A pair of strong arms wrapped itself around the delicate waist of the Dragonlord of the Blazing Void. 

Crash

A German suplex sent the Dragonlord of the Blazing Void deep underground up to her knees only for a purple flash to send the claw wielder flying away. 

"They're not trying to kill each other, right?" Kiba whispered as he watched his classmates disappear in cyan, purple, and flame-tinted flashes or blurs on the battlefield. 

"Oh? Well, Issei-kun and the others are just playing around," 

A black blur almost hit the blonde swordsman if not for the claw wielder twisting in the air and landing on the ground like a cat with a pair of draconic wings on his back. Disappearing with a cyan streak, the claw wielder caught the Dragonlord of Storms and the Blazing Void in a brutal Lariat each, sending them reeling to a nearby wall. 

Rias winced as the sound of a broken wall echoed in the training room only for Mei to reappear in front of the helmed man, initiating a dance of blade and claws. Ice met and danced with energy as the two sped up. The man turned into a cyan blur while Mei's form flowed and danced like a river. 

"Okay, that's enough! We have guests!" Seele called out, clapping her hand just as a claw of ice almost met Mei's chin while a katana almost clipped his side. 

"Ah!" Kiana meanwhile fell and landed on top of Issei, her greatsword stabbed near his head. 

"What's the big idea?!" Kiana asked with a pout, sitting on top of Issei's torso. Her chest heaved, rising and falling with each breath as sweat fell from her skin. 

The hooded helmet the young man wore disappeared, revealing the face and blue eyes of the Dragonlord of Dragon's doom. 

"Rias Gremory," Issei greeted as he reappeared in a cyan streak beside Mei. 

"Human," A beautiful white-haired girl dressed in a gothic dress said with a smile. Her red eyes filled with respect and adoration for the human. 

"Thank you, Luna," Issei said with a smile, taking the towel in Luna's hand before drying his hair. "So, what brought you here, Rias," Issei asked, looking at the Devil in front of him. His soul claws, long since turned off as his gauntlets disappeared, revealing a pair of scarred lower arms. 

"We just wanted to visit and ask you some questions," 

"Oh?" The Dragonlord of Doom looked at the young woman by his side, ignoring how Kiana started to lick and nibble on Mei's neck. 

The young woman nodded, and he turned around to face the eyes of the Devils in front of him. 

"Mind if we move this conversation to the living room?" Issei asked, looking at the group of Devils. 

Bonk

Mei approached the group, carrying a knocked-out Kiana in her back. 

"I'll take Kiana to her room," Mei said as she disappeared in a purple flash.

 "Was that Hiraishin?!" Rias excitedly asked, her eyes sparkling with excitement. 

-=-=-=-

"Did you get Isekai'ed to Fairy Tail?!" Rias asked, slamming her hands on the table while leaning in. Her eyes sparkled as she got closer. 

"Back off," Luna said, getting between Issei and Rias. "Kya!" 

Pulling the red-eyed woman to his lap, Issei gently patted and rubbed her head as if she were some cat. 

"No, I did not get Isekai'ed to Fairy Tail, Rias," Issei said with a smile as Draco grinned and laughed mockingly at Koneko as he monopolized the bowl of sweets. "If I did... I would have had a harem already," 

"Ehem," 

"I know what I said," Issei said with a smile as Luna in his lap scoffed but leaned to his palm. "how did you reach that conclusion?" Issei asked, looking at Rias as Seele took a seat by his side. 

"Well, you ate Riser's flames," Rias said, waving her hand and showing a magical event projection. 

"I'm surprised you did not turn that fried chicken into a food source," Luna said, memorizing the face of the blonde. 

"I was tempted," Issei said with a shrug. "Well, if those two did not appear then we would have a high-class devil specimen to study," Issei said with a smile, unknowingly sending shivers down Kiba's spine. 

"You're a vampire!" Rias whispered, looking at Luna. 

"Is there a problem?" Luna asked, her voice turning cold as she focused on Rias. 

"Behave," Issei's voice was firm and retained a warm tone but Luna behaved. 

"I did not mean to offend you," Rias said, looking at Luna. "One of my adorable peerage members is a vampire and he is currently sealed away because of his sacred gear."

"Interesting," Luna said as her eyes glowed ominously.

"Luna, behave and don't trouble our guests," Another voice echoed in the room. 

The third vampire of the Undead Legion and a young woman looking a lot like Kiana but with a single braid. She walked with an elegant and mature grace while carrying a plate filled with snacks. Her blue eyes were filled with life, ironic of her true nature as a vampire.

"I apologize for my sister," She said with a bow. "I am Kallen, Kallen Sundenjaeger, it is nice to meet Lord Issei's guests," While her smile looked beautiful, the rest of the Occult Research Club could not help but feel as if they were being analyzed for weaknesses. "Lord Issei, the reports are ready," Kallen said as she lowered the cups and pot of tea on the table. 

"Thank you, Kal," Issei said with a smile before turning to Rias. 

"Vampires, it's hard to find and befriend them... to have them under you," 

"My reasons are my own," Kallen said with a smile as she stood behind the couch. 

"So, your dream as a harem king has been achieved, Issei," Rias said with a smile. "Congratulations in your engagement," 

Silence

That was the wrong thing to say. 

The smile on Rias' face disappeared as an unstoppable feeling of dread excluded the adorable little bean beside Issei.

The Dragonlord of Life and Death along with being Issei's soulkeeper lowered the cup of tea in the plate on her hand. 

Clink

The sound echoed deep into their very soul. 

"Would you kindly explain, President Rias," Seele said with a sweet smile as she opened her eyes, revealing a pair of soulless orbs. 

Luna, the vampire in Issei's arms wisely stayed quiet as she released her vampiric aura, her eyes glowing ominously. 

Kallen, behind the couch, sighed as she massaged her temples. Why was her master so sinful? 

The leader of the undead Legion shrugged and nonchalantly tasted his tea, uncaring of the sources of Vampiric, Soul, and light magic flaring beside him. 

"Lady Seele," Rias paled as she finally processed who the adorable thing beside Issei was. Seele Vollerei, a descendant of the Grecian ruler of the underworld. "Issei here is engaged to Sona Sitri after he beat her in chess," 

"Issei," Seele called out, turning to Issei and alleviating the pressure on the occult research club. 

"Well, Sona challenged me to a chess match and I tricked her into admitting defeat," Issei explained. "I did not know that me beating her would lead to that," 

"I am upset," Seele said, making it clear to the Dragonlord of Dragon's doom. "Hmph!"

"Fine, sorry," he said, gently lowering Luna while ignoring her pout and gently wrapping his arms around Seele. The adorable munchkin's face did not change, keeping the pout as her arms wrapped themselves around the back of the Dragonlord of Dragon's doom, pawing at it. "Kallen," 

"Understood," 

Kallen gave a bow toward Issei as she looked at Luna. 

"Come, Theresa," Kallen said, dragging her sister along as she exited the room, knowing her lord's attention should focus on Lady Seele for now. 

"Sis! Let me go!" 

"You still haven't finished your homework, Theresa!" 

"No!"

"Sorry about this," Issei said, keeping his arms around the pouting Seele as she moved to his lap, facing him with her face buried in his chest. 

"You two are very close," 

"We have a special relationship," Issei admitted, looking at his schoolmates. Seele, quite upset, said nothing as she clung closer to him. "But regarding your question earlier, no. I never got isekai'ed to Fairy Tail and I am lucky to get isekai'ed to where I ended up," He whispered, looking at Seele's pouting face. 

They traveled and helped each other a lot, braving countless adversaries, and despite how much it hurt... he would never give it up. 

"But I did get Isekai'ed," Issei revealed as he felt the upset Seele pout at him. Well, there goes his night later. 

"I knew it!" Rias excitedly whispered. "What kind of world did you get Isekai'ed to? Are you a hero? A villain? Did you have a harem?" 

One by one, Rias' questions flowed from her mind as Issei tried his best to answer them. 

After a stressful event, Issei sighed and looked out the window of his current residence in his new estate. 

"Issei..." Seele whispered, peeking her head out of the blanket. "Do..." 

"Seele, I did not know. I promised you, right," he said with a smile, gently caressing her cheeks. Feeling the warmth of his hand, the princess of the Underworld leaned into his palm. "I will only allow those you approve and I will always put you first," he said with a smile as he looked at her. 

He could lose them all but not her. Never her... it must be their soul-wedded bond talking but to him, she is someone unstoppable. Yes, both he and Seele are technically married. The procedure she did to save his soul because of his stupidity required an intimate bonding and since she protected his soul, her soul and his bonded. 

It led to a lot of complications but it was fine with him. 

"I know... but... I'm sorry... you always..."

"You're not a bother, Seele," Issei said with a smile. "I will always be with you," he said with a smile, pulling the young woman close to his body. "No matter what," 

For a split second, Seele's aura changed, revealing the inner aggression she always held back. Veliona, the split-personality existing inside Seele reemerged and in an instant, The Dragonlord of Doom found himself pinned and used as a chair of the inner personality of his deerest Seele. 

"Flirting with other girls even if you have Seele?" A lone dainty foot pressed itself on his face as Veliona, inhabiting Seele's body, gave him a cruel smile. "Have you no shame, Hyoudou?" 

"Stop grinding on my crotch then," Issei shot back, enjoying how Veliona turned red. 'How cute,' 

Unlike Seele, Veliona can be described as direct. She is more open to her thoughts compared to the gentle Seele but what endeared her to Issei was her innocence. Compared to Seele, Veliona was more innocent and adorable than the Dragonlord of life and death... well, Dragonlord of Life. 

"S-stop your talking, human!" Veliona shouted with a blush as she looked around before gently curling on top of him. "I... I'm only doing this because Seele likes it!" 

"Yes, yes... sure. and I'm not a pervert," Issei said with a grin as Veliona moved, wrapping her arms around his shirt and pulling it down. 

Chomp!

Veliona, unable to retort, settled on biting down on his skin. 

"Stupid... unworthy... pervert..." With each word, teeth marked his skin, leaving a mark for all to see before soft lips pressed on them, signifying the return of the gentler Seele. 

0--0-0-0-0-0-0

Issei blinked as he entered the classroom he was assigned to. He ended up staying up the entire night to fill out some paperwork and research notes from the Research and Development division of the Legion. Instead of the usual red shirt he wore, he changed it to a blue one. His newly-made Deathknight relic rings decorated his right hand's pointer and ring fingers.

"Hyoudou..." 

"Issei, you traitor!" 

"What the hell, man?!" 

The Dragonlord of Dragon's Doom looked at his friends, wondering what was going on. 

"Had fun, last night?" Kiana teased as she passed by him. 

"Ara, Ara~ Naughty Issei," Mei said as she went to her seat. 

"Hyoudou," Kiryuu said, pointing to her neck. 

Reaching a hand out for his neck, Issei blinked. Several teeth marks decorated it. 

"Catch," Raising his hand to catch a pocket mirror from Kiana, his eyes widened as he saw the reflection. 

Teeth marks and hickeys decorated his neck and there was even a lipstick mark on his collarbone?! He knew where the teeth marks were from along with the hickeys. 

"Hmm..." Tossing back the pocket mirror to the blazing void Dragonlord, Issei ignored his classmates and went to his seat. 

'How should I build a connection with the other factions...' Issei thought to himself. While he already has a way to connect with the Shinto, heaven, and possibly the underworld, there are still many factions he needs to connect with.

Sighing to himself the young undead noted these things away for later. His body still needed healing for now. 

-=-=-=-=-=-==-==-=-=-=-

Shadow hunting, an ancient art practiced and created by the Dubellemonts. In the current age, there were only two people who practice the ancient art. Issei Hyoudou, the Hero of Falconreach, and Symone Dubellemont, Scion of house Dubellemeont. 

A blur of white and blue danced across the shadows of the underworld as a stray devil whimpered as one by one, its limbs were crippled. 

"Sister is far too cruel," The Stray devil froze as he heard a new voice. his demonic form, a mixture between a human and chimera looked at the newcomer. A beautiful young woman with white hair and red eyes dressed in a gothic dress. "I wanted to hang out with Master Issei, later!" 

"Focus, sister," Another voice called out as the Shadow hunter revealed herself. "Master Issei will be fine," 

Kallen Sundenjaeger, a member of a clan present on Doomwood closely tied to the Dubellemonts. Instead of her sister's chainsaw sword, she wielded a pair of pistols. 

"But sis!" Without missing a beat, Luna moved, driving the chainsaw sword deep into the Stray devil's body. The teeth of the chain sword ripped and tore through flesh and bone, spraying blood everywhere. "Bleh! Disgusting!" The vampire said, spitting the blood that entered her mouth. 

"You Bi—," A magic circle above the stray devil disappeared as a smoking barrel shattered it with ease. "Impossible!" 

"That's unsanitary, Theresa," Kallen said, ignoring how her sister hacked and slashed at the stray devil with an annoyed look on her face. 

"Sister! Can we go eat sweets later?" Theresa asked with a sweet smile as she pressed the chainsaw's teeth on the body of the devil, slowly watching as it rotated and tore through flesh as slowly as possible. 

"Yes, we can. After we finish the contract," Kallen said, shaking her head at her sister's antics. 

"You're the best, sis!" 

Having enough of her sister's antics after a few minutes, A beam of black magical energy escaped the barrel of her gun, leaving a clean hole in the devil's human head. 

"Aww! it's broken!" The blood-covered Luna whined. 

"Sister... clean up first, okay. I'll take care of the contract," Kallen said, raising her hand and catching a chess piece, a single pawn piece. 

"Of course, sis!" Luna said with a smile before she looked at the shattered remains of the Stray Devils. 

Meanwhile,

Tut, the mummy, smiled as he looked at his computer. It took a while but his natural intelligence and passion for learning finally allowed him to master the use of the internet. As his hands typed on the keyboard, a sudden error appeared on the screen. 

'A hacker?' The mummy thought as his fingers danced along the keyboard, typing the necessary commands. 

An image of a bunny overlapped with the loading screen and a grin appeared in the mummy's bandaged face. 

'It's nice to talk with you once more, Lady Bronya,' Tut typed. 

'Don't tell the others, okay? I'll be taking your original role,' 

'Glad to have you on board,'

Far away over the seas and inside a hidden safe house, a girl smiled as her gray hair draped over her shoulders. A soft smile decorated her machine-like face as countless corpses decorated the hallways leading to the computer room. By her side, a mechanical dog sat in attention. 

The young woman's hand held the handle of a pistol and her face went cold as she looked at the twitching hand of a body near her. Raising the pistol, she pulled it without hesitation and watched as a hole formed on the body's head, killing him in an instant. 

Walking away, the young girl coldly passed through the countless bodies in her way.