The Testament of Sister New Devil (2015)

When Mafuyu Oribe and her adopted sister Tomo rescue a strange wounded man, they have no idea what they’re getting involved with or what the consequences will be. Alexander Nikolaevith Hell is an Iron Qwaser, one of many opposing factions of super-warriors.

High school student Michio Kaga was wandering aimlessly through life and the Internet, when he finds himself transported from a shady website to a fantasy world — reborn as a strong man who can use "cheat" powers. He uses his powers to become an adventurer, earn money, and get the right to claim girls that have idol-level beauty to form his very own harem.

The story takes place in Japan in the early 21st century, in an alternate reality where the Tokugawa Shogunate has remained in power. In this reality, student councils are tasked with oppressing schools. Yagyuu Muneakira is a high school student who rebels against his student council with the help of girls who've had the names of famous samurai heroes passed on to them.

Three months have passed since the Demon Lord was struck down, and the Demon Realm is holding a tournament to select his replacement. The leading contestant is Helck, a human hero who claims to hate his own kind. Some aren't happy with the idea of a human becoming the next Demon Lord—especially Vermilio the Red. She wants nothing more than to protect demonkind and prove Helck to be their enemy, even if she has to rig the competition to do it!

Kojou Akatsuki's days as an ordinary high school student in the Demon District of Itogami Island come to an abrupt end after a fateful encounter leaves him with the remarkable abilities of a vampire. It isn't long before he is thrust into the center of attention when it is discovered that he is the fourth primogenitor, an immensely powerful vampire whom most consider to be merely a legend. Fearing Kojou's destructive potential, the Lion King Organization sends in an apprentice sword-shaman, Yukina Himeragi, to monitor, and should he become a threat, kill the boy deemed the world's most powerful vampire. Forced together by circumstance, the two form an unlikely alliance as Kojou comes to terms with his abilities and they both struggle to protect the city from various emerging chaotic forces.

When it comes to the fantasy MMORPG Cross Reverie, none can match the power of the Demon King Diablo. Possessing the game’s rarest artifacts and an unrivaled player level, he overpowers all foolish enough to confront him. But despite his fearsome reputation, Diablo’s true identity is Takuma Sakamoto, a shut-in gamer devoid of any social skills. Defeating hopeless challengers day by day, Takuma cares about nothing else but his virtual life—that is, until a summoning spell suddenly transports him to another world where he has Diablo’s appearance! In this new world resembling his favorite game, Takuma is greeted by the two girls who summoned him. They perform an Enslavement Ritual in an attempt to subjugate him, but the spell backfires and causes them to become his slaves instead. With the situation now becoming more awkward than ever, Takuma decides to accompany the girls in finding a way to unbind their contract while learning to adapt to his new existence as the menacing Demon King.

For 30 years, thousands have traveled to other worlds. The few that return keep the powers they had in those worlds. Akatsuki Ousawa returns from the world of Alayzard with the defeated Demon King's daughter, Miu. Miu pretends to be Akatsuki's sister to hide her true identity. They join Babel, a school for inter-dimensional travelers, and struggle against the student council to uncover the truth behind the school.

Godo Kusanagi, a high school student that kills a god, claiming its power and title of Campione, to slay other gods.

In his past life, he was known as Demon Lord Varvatos, an all-powerful magic user and ruler. But he was lonely after the loss of his friends and loved ones during his rise to power, so in his dying moments, Varvatos cast a reincarnation spell so that he'd get a second chance at just being a normal guy. At first it looks like that's going to work – he's reborn thousands of years later as villager Ard. Unfortunately for him, his memories are still intact and he's not aware just how much has been lost over the time he spent not existing, and it looks like that's going to cost him his normal life.

Natsuru is selected to be a Kampfer, a mystical fighter who has to fight other Kampfers. The catch is that all Kampfers are female, and Natsuru is male... at least he was! Worse, Natusru's best friend turns out to have a crush on his new body.