How To Write A Murderous Antagonist Effectively?

I’m trained to do one thing: kill. I was put into a school where the concepts of love and forgiveness were treated as weaknesses. When I graduated, they told me I’d be lucky to survive; now I’m the best of the best and the person who gets the job done no matter what. I’ve assassinated Presidents, housewives, Navy SEALS and more shifters than I can count. I have more kills than anyone in my business, so when a new order comes in to kill Alpha Gideon, I take it without a second thought. ​He’s a job like any other, but during my scouting, I see something I’ve never seen before. Alpha Gideon isn’t a tyrant or a bully; he’s kind to his Pack. I start asking questions, which is when everything goes to shit. My signal is found, and for the first time in my life, my target has me in his sights. I expect pain and maybe even death, but Alpha Gideon treats me like a welcomed guest; his warmth and kindness open up something inside of me that I didn’t know I had. I should kill him before he changes me completely. I tell him I’m cold and heartless, and he laughs. Loving a mark has never been done, but no matter what I do, every touch sets me on fire and with each longing glance, my past becomes a distant memory. I’m ready to put everything I was aside to stay with Alpha Gideon when the call comes in; my fellow assassins have been called. The bounty on Alpha Gideon has been doubled. I have two choices: protect the man who has opened up my heart or kill the target and get the job done.

This is thriller where the killer murders with put leaving a detail and you wont ever feel bored i guess all of you guys will enjoy reading this

He promised to protect him from a killer. He never said he was one. When journalist Ian Parker witnesses a brutal murder, he should have been the killer's next victim. Instead, he wakes up in the hospital, saved by Zhedya Hunter…a brilliant forensic pathologist, a reclusive CEO, and a man with chilling grey eyes that feel hauntingly familiar. Charismatic and dangerously possessive, Zhedya offers Ian shelter in his opulent penthouse, a gilded cage where every comfort is a chain. As Zhedya's obsession deepens, Ian's career skyrockets, with damning evidence against the city's most wanted criminals mysteriously falling into his hands. But each exclusive story comes with a price: a fractured memory, a drugged haze, and a growing pile of bodies connected to anyone who threatens their twisted paradise. Now, Ian is trapped in a nightmare of luxury and lies, unraveling a truth more terrifying than any headline: his savior is a predator, his sanctuary is a crime scene, and the man who claims to love him is the most prolific murderer he will ever interview. Learning how to love a murderer is easy. Surviving him is the real story.

Introduction：Xienne Collins, a typical college student, is beautiful and smart. Known for being kind but being abused by her classmates whom she considered friends. Her character was trampled on. Not a day goes by that she is not begrudged and bullied by them. She endured it for too long and told herself she would not retaliate or will take vengeance. But the day came when she was filled with what her classmates were doing. She wanted to kill them all and planned carefully how she could accomplish this. She killed her classmates one by one. She writes in her diary what she did to her classmates for satisfaction about what she had done to them. Little did she know someone is watching her.

The Alpha's daughter of a rival pack, the last living pack member of the Blood Moon pack was taken by The Black River Alpha and was going to be forced to be mated to one of his three sons when she turned 18 to use her strong bloodline for heirs. There starts to be random disappearances and then people start turning up dead. No one has any clues or ideas of who is doing it. No one suspects that the weak, scared, timid girl was actually a trained assassin since birth, and she is out for a revenge she has planned since the day she was taken.

What better defines cruelty than an Alpha who killed his own brother and nearly wiped out an entire pack? When the humble Vance pack is almost annihilated by Alpha Lucien Draegor, Seraphina Vance receives punishment instead of mercy. She is dragged into the Draegor estate and forced to live as nothing more than a maid. Fueled by deep hatred, Seraphina is certain of one thing: she will kill Lucien Draegor for reducing her pack to nothing. She will see it through to the end, or she will die trying.