Hi, guys! So I've decided that I'm going to give Issei a Servant, but I'm not saying which.
A few weeks after meeting Issei, Shirou and the Einzbern-Emiya family went to school. While the girls went to a local elementary school, Irisviel and Kiritsugu convinced Shirou to go to Kuoh Academy, a prestigious school which only recently allowed male students. It was also the same school Issei went to.
During those weeks, Shirou had gotten to know him better. Issei's parents had warned Shirou that Issei was a pervert of the highest order and that it would be better if Shirou would stay away from their son. Shirou merely laughed and promised he'd be careful. Afterwards, Shirou gave Issei a little "talk" about his lewd behaviors around Shirou's sisters. Once they're talk finished, Issei was slightly afraid of Shirou and swore he would never do that. He was also interested in a magical smell coming from him, the smell of a powerful smell. However, Shirou could tell that he was just a regular human.
Upon starting school, Shirou had once again gained his title as the School Janitor. He also heard names such as the Kuoh Brownie and many others. Shirou had also tried out in the kendo, archery, and martial arts clubs, easily becoming the best in there but getting bored and leaving. However this caused all of the clubs to want him even more, sending girls to constantly badger him about joining.
School work was easy, as he had done high school before. Soon after, Shirou had raised to to top of the class, even outshining the class president, Sona Shitori. This caused the girl to give Shirou death glares at every opportunities.
Speaking of Sona, Shirou had detected strange demonic magical energy from her and other girls. From what Shirou's research told me, they were devils the demonic beings apart of Judeo-Christian Faction of the supernatural world. Multiple mythos were turned into factions which were vital parts of the supernatural world. The Judeo-Christian Faction is the most powerful of them all.
Anyways, Shirou had become one of the most popular students in the school. Since this school was a formerly all girl school, all the girls like to crowd around potential boyfriends. Shirou was one of those potential boyfriends, on level with another student, Kiba Yuuto. He was another devil but had a sword like smell like him. Normally, Shirou would just befriend him, but he remembered just how perverted the female students were. To avoid a yaoi outrage, Shirou kept his distance from him.
Shirou was still friends with Issei, but frowned at his and his friends, the Perverted Trio,'s actions. He would constantly help the girls punish the three, which means made his popularity rise even higher. One day, Shirou was walking the school grounds when he found those idiots running from the kendo team.
"God dammit," Shirou sighed, somewhat tired with their behavior. He quickly took his school bag and began swinging it around. He quickly smashed the bag into the three. Issei and his friends, Matsuda and Motohama, fell on their asses. This allowed the girls to catch up with them. Recognizing Shirou, they smiled happily.
"Thanks, Emiya-kun!" they cheered. Then they began beating the crap out of the Trio.
"Your welcome!" Shirou smiled, walking away while hearing the sounds of his beaten friend.
Scene Break
"Emiya-kun!" Issei cried. "Why didn't you save us?"
The girls had beaten them badly, but Shirou had decided to take pity on them, treating their wounds.
"Because you deserved it," Shirou said.
"You dammed handsome!" Issei's acquaintances cried. "You're the reason we don't have our harems and girls crowding around us."
"Really?" Shirou raised his eyebrows. "And here I thought it was just because you all were complete losers. You realized that if you guys keep your horniness down, you could get a girlfriend who would actually let you do perverted stuff that you dreamed of."
The boys fell onto the ground, defeated. Well, Issei still stood up. "Nice try, my friend. But I have a girlfriend."
Shirou and the others stared at Issei in shock. While the two perverts were crying, Shirou smiled at his friend. "Good job, Hyoudou-kun! I'm really happy for you."
Issei smiled, proud of his friend's praise. However, the Perverted Trio suddenly felt a dark energy. They turned back towards Shirou, who was smiling darkly.
"However," the magus said, darkly. "You need to promise me that you are a complete gentleman."
Issei shivered. "O-Okay. Please don't kill me!"
Suddenly, the magical smell of a fallen angel came into the area.
"Hi, Hyoudou-kun!" a girl came, waving her hand.
"Oh, there she is," Issei said, his cheerfulness restored. "Yuma-chan!"
The girl smiled, jumping to give Issei a hug. She wrapped her hands around Issei, but she stared at Shirou, as if determining if he was a threat or not.
Shirou narrowed his eyes, then instantly smiled happily. "So this is your girlfriend, Hyoudou-kun? It's nice to meet you. I'm Emiya Shirou!"
The girl blinked and nodded. "Amano Yuma." The girl then turned towards Issei. "C'mon, Hyoudou-kun! We're going to be late!"
She then proceeded to drag him away from the group. The rest of the Perverted Trio left as well. Detecting no one in the area, Shirou created a bird homunculus familiar with a silver wire.
"Follow them," Shirou ordered. "Alert me if anything happens."
The bird flew into the horizon, stalking Issei and his fallen angel friend.
Scene Break
Suddenly, Shirou was alerted of a danger to Issei. Wanting to protect his friend, Shirou teleported to the area. Unfortunately, he found Issei laying dead while Yuma floated above him in her fallen angel form.
"Yuma, you bitch!" Shirou shouted. He rushed forward and slash at the fallen angel with his twin swords Kanshou and Bakuya, who escaped just in time.
"Shit!" Yuma said, escaping from her attacker. "You dare attack me, the fallen angel Raynare, you stupid human!"
Yuma, or rather Raynare, created a spear of light tried to slash at him, but Shirou merely sliced the spear in half. Shirou, annoyed, gave the fallen angel a kick and was sent into the nearby forest.
Shirou knelt by his dead friend. His body had taken massive damage from a light spear, but Shirou swore that he would resurrect him once this was all over. Shirou rushed into the forest and found Raynare barely standing.
"You damn brat," she growled. "What the hell are you?"
"Oh, just shut up," Shirou said. The magus threw his swords at her but Raynare managed to deflect it with another light spear. However, she found Shirou gone.
"Behind you," Shirou said.
Raynare turned, panicked. Shirou cut her wings off with the holy sword Caliburn. He then stabbed her stomach and gave her another kick. He began walking slowly towards the fallen angel, who was cowering and crawling to get away.
"No," she screamed. "No, stay back!"
"Die," he said, pointing the sword at her and thrusted. "Caliburn."
A dazzling light erupted from the sword, blasting the fallen angel. As the light hit her, she screamed, "Kalawarner! Dohnaseek! Mittelt! Get me out of here!"
The light faded and Shirou gritted his teeth. "Fucking damn it!" he cursed, slamming his fist into a nearby tree, sending it crashing down. Shirou saw it. After briefly being hit by the light, a teleportation circle had appeared, meaning he had let the bitch escape. "I was careless. I should have put up a bounded field to keep her in."
Angry at himself, he walked back to Issei to resurrect him when he felt a demonic presence.
'I know this aura,' Shirou thought, running at high speeds to find Rias Gremory along with some other devils by Issei. Rias was currently standing over Issei's dead body, holding out eight pawns and chanting. Light was erupting from Issei's body.
"Gremory-sempai," Shirou said, getting the attention of the others who he recognized as Akeno Himejima, Kiba Yuuto, and Koneko Toujou. "What the fuck are you doing?"
Before anyone could do anything, Kiba stared at Shirou in anger. "That's a holy sword!" he shouted, rushing at Shirou with incredible speeds. However, to Shirou, it was quite slow. He easily blocked the strike with Caliburn and disarmed the attacking devil. Shirou pointed his sword at Kiba's neck.
"I'm going to ask one more time," Shirou said, slowly. "What. The. Fuck. Are. You. Doing. To. My. Friend!"
Rias stopped chanting and looked at Shirou. "Emiya, it's alright. Look, he's alive again."
Shirou looked at Issei, who was indeed breathing again. Sighing, he put away his sword. "As thanks for reviving him, I won't kill you. But I want answers. Now."
"Oh my," Akeno said, smiling evilly. Shirou was briefly reminded of his ex, the nun Caren Hortensia. "Emiya-kun seems to be very scary."
"A church member?" Koneko asked without emotion. Shirou was once again reminded of someone he knew, his maid Leysritt.
Rias turned towards Kiba, who was still glaring at Shirou. "Kiba, please take Issei back home. Emiya-kun. Please follow us. I will explain everything."
"Following devils," he said, before shrugging. "Fine, I've done stupider things."
Rias blinked. "You knew we were devils?" she asked.
"I have the ability to sense the supernatural," Shirou said. "Now, let's get going. I'm eager to learn exactly what is going on."