Background:
Born in a wealthy family who previously run an underground assassin organization. His retired grandfather, Xing 雷煋, was one of the bosses, which Xing made a deal with the organization to never interfering with his family again, by doing one last mission and then cutting off one of his arm. With only one arm left, Xing's quirk became useless ever since.
Despite being same as quirkless, Xing still able to train his grandson, Xian, of all the assassin technique he know.
Xian was a sensitive child, as he always feel sad whenever he saw his grandfather's missing arm, even though he understood that it is for the sake of their family. Which, slowly influenced his quirk to naturally take on his sad emotion.
Quirk: Dark Tendril
Xian is able to conjure crystal-like tendril, using his mental focus to "grow" them out from his body.
The tendril will fall apart if not connect to his body. (However, a drop of his blood can be used to temporarily maintain the tendril from breaking apart)
The tendril being formed are mostly rigid, which cannot change at his will. So, he mostly shape the tendril in simple spike or blade form.
The tendril's base color is based on the emotion energy that Xing provides: sad = black, angry = red, happy = yellow, worry = gray, jealous = purple, etc
Although rare, but when Xian is in trance form, all his tendril will become transparent. His black hair would turn white as a result. This trance form is one of the secret technique that he learned from his grandfather.
At his teen stage, Xian entered UA to become a hero to redeem his family past deeds. Being acknowledge that Xian will be a greater villain than hero, he quoted his grandfather saying "We are our own greatest enemy", so he becoming a hero means one less villain.
Techniques:
Shadow Crawl - forming spikes downwards to move himself, mostly serve as a maneuver technique with some offensive purpose
Dark Sword - create a simple black blade with handle, to be used in combat like a sword.
Blood Stinger - shoot out a sharp tendril that fused with a drop of his blood.
Jump Spike - Stinger Spike that can change to another direction once.
Stinger Thorn - massive Stinger Spike
Hell Stinger - massive Stinger Spike shooting from ground below
Blade Wave - using Stinger Blade as sword wave
Blade Storm - massive Stinger Blade spinning around him
Killer Trance - render all his tendril to be transparent and unlikely to be detected by unrefined senses.
The Four Masks 四面具
After his grandfather pass away, he personality split into four, with melancholic as his base personality.
Through transition of his personality, his quirk changed into different form. He then discovered that his quirk is like a special kind of dark matter exclusive to him, which he can make use of this mystic matter to create other forms such wind, fire and glass.
悲痛之黑刺（剑）
Stinger of Melancholic, his most familiar move, the sharpness is based on painfulness of his sorrow, He must redirect his sorrow towards enemy after the blade is formed, otherwise the blade may hurt himself.
情趣之步风（脚）
Wind of Sanguine, requires the emotion of happiness and playfulness, transform into wind. This personality enjoys making fun of the enemy with this illusive ability.
霸气之烈火（拳）
Flame of Choleric, requires the emotion of anger or adrenaline to conjure magical flame. The flame may become too powerful and burn himself especially when hatred is mixed into the emotion. If the flame is mostly adrenaline based, it will greatly boost the fire power and resistant towards the flame.
宁静之镜水（盾）
Glass of Phlegmatic, requires the emotion of peace and quiet. One of the most powerful ability, but the most difficult one as well. When in tranquility, this automatically heals his own wound. If enough meditation, Once reached the realm of nothingness, hexagon prisms are formed around him, which nullify all damage as well as incoming attacks.
求死绝念 刀镜贯灭
Death Wish, Crystal Blade = Sorrow + Emptiness >> using utmost sorrow to kill himself and surrounding enemies and allies, but the Glass nullify the damage so he himself is unharmed.
恨恶嗔伤 猛火旱地
Hellfire Wrath, Scorched Earth = Hate, Forgive >> ignite the greatest hatred on a single Flame, burning himself unless being healed using the Glass.
狂笑杀戮 风围血刀
Songs of Saddist, Scythe Wind = Happy + Pain >> taking the role of a sadist persona, feeling the joy upon causing pain on the enemy, usually a follow up attack, making use of enemies' pain upon themselves.
冷眼冰恨 黑炎送剑
Coldest Void, Dark Flamberg = Sorrow + Anger >> cold hatred that engulfs the Blade with burning black flame, causing damage over time until his hatred is gone.
狂热四方 群寻弹火
Ardent Burst, Firestorm = Happy + Adrenaline >> a burst of overwhelming excitement that unleash sudden massive unstable fireballs that need to controlled using the Wind to home into the target(s).
宁神玄境 真假世界
Ultimatum, Mirror World = Peace + Joy >> the most difficult mental state to achieve, creates a number of illusions, which the realism is based on the mental state of the observer: the weaker the mental state, the harder to distinguish the fake. To some extend, if the mental state is too weak, the illusion can even cause physical harm towards the enemy.
