The Insignifcant Female Supporting Character Actually Became a Bigshot in the Novel! - Chapter 142 - : Stylist

A ritual gone wrong gave him the world's deadliest Class—now all he wants is blood.Zeth stole the most powerful ritual magic in the world from a mad cultist. A Class that's fueled by the blood of his enemies and human sacrifice. One that's illegal to use, punishable by gruesome death. And now that he has it, he's faced with a choice: hide away for the rest of his life from those who would hunt him down, or embrace the power, becoming the hunter to get revenge on the murderer that stole his friends' lives.For Zeth, that's no choice at all.His enemies have to die. And he plans to use every drop of blood, eldritch ritual, and demonic summoning he can to kill them.

This thought had grown deep in William’s mind!

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

[Congratulations, Host! You have transmigrated to a magical world.]Good![Congratulations, Host! You have received a transmigration gift: SSS-tier identity—Prince of Ilan!]Very Good![Congratulations, Host! You have received a transmigration gift: SSS-tier Gift—Marty Bloodline!][Level-up Speed ×10, All Spell Power ×10]Very Very Good![Generating Bloodline…][0%... 5%... 35%... 42%...]Can’t wait any longer~~~[Warning! Warning! Warning!][World backlash detected! System is about to collapse!][Host, please evade! Host, please evade!]Wait, are you kidding me???[Bang!]And just like that, you transmigrated into a magical world.With the system gone, despite your extraordinary talent, you chose to lay low and survive.The world is vast, but staying alive is the top priority.Years later, a rumor began to spread around you:“Wait… you're telling me that useless prince… has been god rank all along???”