MTL - Honkai Q&A, Starting with Kiana - Chapter 219

In a future timeline, the earth was visited by a species known as the Slarkovs.
Having lost their home planet and in search of a new one, earth was the next habitable planet for them.

Humans and Slarkovs made a deal with each other in return for the Slarkovs living on earth.
The Slarkovs traded their technology and knowledge for a new home.
They were similar to humans except for some of them who had slight differences so fitting into the society wasn't a problem.
Over the years Slarkovs and humans began to mate with one another and reproduce offsprings.
This in turn created a new species known as the mixed-blood.
Centuries later mixedbloods could tap into their bloodline and perform unimaginable feats.

Gustav born into an age where bloodline determines everything, struggles to fit with a useless bloodline.
His bloodline only grants him the ability to change his hair color, destroying his hopes and dreams for a great future.
His fate is turned around when an unexpected situation leads to him finding a system that grants him the power to unlock and upgrade bloodlines by completing quests but he's baffled by two quests with a five-year deadline. Success will grant him unimaginable rewards...
But only one thing awaits him if he fails... Death!

Follow Gustav on his interesting journey filled with unprecedented adventures, danger and death, maybe?

He was the crown prince of the shadow realm and the lord of wrath, Azrael. All creatures, demons, mortals, even angels feared him. However, everything changed after he went for a secret mission in the mortal realm in order to expand his seven sins power.Hiding his identity among the mortals, the vampires were attracted by his royal blood. The mortals were either jealous or admired his abilities. The angels were curious about him. The demons wanted to kill him and take over his power.Little did he know, he had another hidden power sealed inside of him. Something terrifying that could turn him either into the ruler of the three realms or an evil that could destroy all beings.--------------Tags: Mature Content , Comedy , Tentacles, Monster Girls , Yandere , Succubus , Magic , Demons , Angels , Hybrid , Hiding Identity, Goddess , Devil , Battle Academy , Beasts , Action , Mystery , Overpowered , Strong to Stronger , Harem , System , Servants , Handsome Male Lead , Smart Male Lead and a little bit of Slice of Life.

Ren has never known kindness. He grew up alone in the slums, learning to survive by staying out of sight and trusting no one. One night, he stumbles into a strange tunnel and finds a hidden shrine forgotten by time.There, he sees a black cat with golden eyes and hears a voice inside his head.The shrine is more than it seems. So is the cat.As Ren is pulled into something ancient and mysterious, he must decide if he's willing to take a different step in life or keep running from the world that hurt him.Because the city doesn't care if he lives or dies, but something in the dark might.(No system, no isekai, no reincarnation, no regression, no harem. The story focuses on mystery and character development.)

Since childhood Gu Wuji has regularly encountered ghosts and was one day involved in an infinite world of terror, just– I treated you as an evil spirit, why do you want to hug my thigh?

- Description from Novelupdates