Crazy Detective - Chapter 8: The Shameless Are Truly Invincible

Summoning ceremonies can freely call forth even “those which lurk in the depths beyond the gods”. One boy has top-level abilities even among the cutting-edge summoners who can use those ceremonies. He is Alice (with) Rabbit aka Shiroyama Kyousuke. But this strongest boy summoner has a single fatal weakness. Certain “cursed words” spoken by girls: “Help me.”

When Kyousuke hears those words from Meinokawa Higan, a girl brought to the verge of death, he throws himself into a city where three great summoner forces clash!

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

Getting the [Boosted Gear] is expected for Issei. What if he gained it a month early and another one as well? Let the Games Begin... IsseiXHarem (if it wasn't, it wouldn't be DXD). Now has a TVTropes page! Getting the [Boosted Gear] is expected for Issei. What if he gained it a month early and another one as well? Let the Games Begin... IsseiXHarem (if it wasn't, it wouldn't be DXD). Now has a TVTropes page!