Dxd: A demon Among Devils - Chapter 29: []:

Way, way, and very way before I was even born, my world was invaded. Actually, not just my world, my entire damn universe was overrun by another, led by a single race that called themselves the Eternals.And they were prepared. Very prepared. Every life we lost in the war against them was used by them. They didn’t just kill people, they captured their souls, forged them into Phantoms, and used the souls to twist beasts into Abominations. Our dead became their army.Three hundred years later, I was born. A guy with way too much energy. Sitting still? Impossible. Taking it slow? Not happening. I was always moving, always ready to burst into action. Then I awakened, and got a talent too.My Talent's Name Was Generator.Because of it I never ran out of energy. Ever. My muscles? Supercharged. My healing? Faster. My stamina? Please, I had no idea what being tired even felt like.So if the universe wanted to throw an endless war at me?Fine. I’d throw everything I had right back.I wasn’t born a hero. Never wanted to be one. But this war? It wasn’t just my universe’s fight anymore. It was mine. The Eternals made sure of that when they took my parents' souls.

The protagonist is a guy who is among the stupidest of the stupidest in the school. In this school, your grades can, under the supervision of teachers, take a virtual form to do combat! However, if you leave an examination half way, you get zero marks. A bright and cute girl, Mizuki Himeji, was having a high fever during the examination. Despite her potential to be the second highest scorer in the level, she obtained zero marks for having left due to her illness and is thus allocated to the worst class, class F.

Grades mean almost everything. For Class A, they have a smart-looking teacher, a plasma TV as big as the entire wall as their blackboard, personal laptops, personal air-cons, refrigerators, adjustable seats and all kinds of different appliances. Within the refrigerator, there are all kinds of drinks and snacks. Their ceiling is made of glass, the wall lets them put up high-class drawings and plants.

As for Class F, the worst class… They have Japanese desks and seat paddings. Their blackboard is dirty and there is no chalk even! Someone complains that the legs of his desk are broken, so the teacher asks, “Didn’t we distribute some glue to stick wood together? Glue it back yourself later.” Another one complains that wind is blowing in from the broken window. The teacher says, “I got it. I will apply for plastic bags and invisible glue to fix it later.” There are spider webs everywhere, not a patch of the wall is clean. A unique moldy smell spreads across the entire room; it must be from the old tatamis used to tile the floor. This is the status of class F.

The protagonist feels displeased at such an arrangement, and seeks help from his friends to try to make a change through summoning war!! And they devise all kinds of plans to try to beat the famous class A, intending to get class A’s classroom and equipment if they win!!

Li Rui had lived to to seventy without any cheat or golden finger. Looking back on his life, he had gained nothing and accomplished nothing. Just as he’s been worn down by the years and resigned to his fate, he unexpectedly awakened the Perfect Life System.“Come on, tell me, how is a seventy-year-old man who’s about to kick the bucket supposed to live a perfect life?!”【You are born with the Martial Bone, and from the moment of your birth, you are destined to become the world’s number one. You gain the talent – Martial Bone.】【At the age of ten, you join a renowned sect and shine in the sect’s grand tournament, gaining fame and attracting the attention of an immortal teacher. You acquire the talent – Divine Skill Mastery.】Looking at 【Gains the favor of an immortal maiden, becoming a divine couple】, he fell silent.“Seventy years old is just the right age to start doing things!”…Many years later.Li Rui finally emerges with the supreme innate Dao fetus, slaying ten thousand demons, breaking ten thousand evils, and ruling over the immortal realm for a hundred thousand years. He is hailed by the world as the Evergreen Immortal Venerable.

Having transmigrated into the world of Journey to the West and become Tang Monk, equipped with a gaming system that allows for battling demons and leveling up, while looting equipment, from then on, the demons on the path to the Western Heaven were in danger. Monk Sha: Big Brother, it’s not good, another demon has been captured by Master. Tang Monk: You all listen to me today, it’s not you protecting your master on his journey to the Western Heaven to seek scriptures, but rather your master has to drag you all along, you know? Without you, your master alone would have fought, uh, made it to the Western Heaven by now...