Dark Knights

Explanation of the story

Jiang Cheng/Wanyin

Abilities

Sandu (三毒, Sāndú) is Jiang Cheng's sword. Which is upgraded to produce lightning just like Zidian can. 

Zidian (紫电, Zǐdiàn) is a family heirloom passed down from his mother, Yu Ziyuan. It sits on the finger in the shape of an amethyst ring but can change into a whip that emits purple lightning. Zidian has the ability to separate the soul from a person whose body has been possessed. 

The Master of Thunder and Lighning.

Hidden and newfound abilities: Good at archery mastered demonic cultivation and unlocked his lightning core. The first person with two different cores.

Manipulative and cunning made a enchantment bracelet and many things. Fire and ice bender. 

Wei Wuxian/Ying

Abilities

Swordsmanship: When he still has his Golden Core, Wei Wuxian is able to use his sword Suibian with high speed and skill. He is still technically able to use the sword without a Golden Core, but without spiritual energy, he would not be able to last long in a fight.

Intelligence: Wei Wuxian is remarkably intelligent and imaginative. In just three months, he invents and develops Demonic Cultivation to kill an entire supervisory office. Repeatedly, he displays excellent deductive reasoning, such as his determination that the Goddess Statue is behind the soul-stealing events on Dafan Mountain, or that A-Qing uses her eye color to feign blindness for her own safety. Through his intuition and careful observation, he can uncannily, discern other's intentions, as he quickly realizes that Nie Huaisang is behind Jin Guangyao's downfall, that Young Master Qin is lying despite his need for help, why the ghost of the man who killed the Hook Hand needs to scream, and more.

Archery: Wei Wuxian is a skilled archer. During the Qishan Wen Clan's grand Discussion Conference, he is one of the four winners placing in first, in the archery competition involving juniors from many clans in the cultivation world.

Paper Metamorphosis: This technique allows Wei Wuxian to affix his soul to a piece of paper. He uses it spy on Jin Guangyao.

Empathy: The mastery of this ability allows Wei Wuxian to view the memories of ghosts or Fierce Corpses, including A-Qing, Nie Mingjue, and Anxin.

Hunting: As a youth, he often enjoys going into the mountains to hunt pheasants.

Charisma: Through his talkative and mischievous nature, Wei Wuxian charms and he befriend many of those around him.

Teaching: Wei Wuxian repeatedly taught the junior disciples how to think critically on their night-hunts, to the extent that they began relying on him too much.

Swimming: As he spent his youth as a member of the Yunmeng Jiang Clan, he is more extremely proficient in swimming.

Alcohol Tolerance: Wei Wuxian can drink large amounts of alcohol while remaining sober.

Hearing: Likely because of his Demonic Cultivation, Wei Wuxian possesses a unique ability to hear nearby spirits. For instance, at the Stone Castles, Wei Wuxian is disturbed by the loudness of the ancestral hall, while to Lan Wangji it is as quiet as a cemetery.

Musical Abilities: He is an excellent flutist, able to play tunes by ear such as a perfect performance of Cleansing modified with a section from the Collection of Turmoil. On a shoddily crafted and out of tune flute, he is also able to play a recognizable rendition of Wangxian, which he had only heard once, years before, while feverish. Wei Wuxian's flute skills are so renowned that his poor performance as "Mo Xuanyu" helps ward off suspicion about his true identity.

The Six Arts: Not only did he master the art of archery and music, he was also good at rites charioteering, literacy, and numeracy.

Nie Huaisang

Cultivation: Upgraded due training. 

Art: Nie Huaisang is noted to possessed a refined taste in art and fans.

Planning: He has patience and determination to execute a revenge plot years in the making.

Acting: Nie Huaisang has exceptional acting abilities, to the extent that he is able to deceive the intelligent Jin Guangyao and Lan Xichen.

Leadership: His true leadership skills begin to emerge at the end of the novel, where Wei Wuxian expects he will surprise many of his naysayers in the future.

Weapon: His fan which controls the air and has hidden blades in thus often used as a boomerang. His spiritual tool is called 枯萎之扇 (Fan of Wither)

This is the story of the young trio who have turned into stone cold men after the deaths of their loved ones...