There's so much good to say for this so unusual drama. It balances between various types of relationships, friendships, surrogate sibling love, parental and filial love, but the characters are often making it unexpected, and it could take rewatches to extract the complete flavor of 不良执念清除师 ( Bu Liang Zhi Nian Qing Chu Shi = Unhealthy obsessions clearers).

There are strange happenings and tendrils of heart blood snaking around the wrist that wields the brush as a tool to give closure to ancient but lingering grief. Reminding sometimes of the Zhang Xiaogang "Bloodlines" paintings. But the grief is not grounded in recent History, but in stories that could be ordinary if they did not gain added significance through the excellent acting of the protagonists. The beauty is also that all these stories are connected, through the investigation of course, but also through the relevance they have to young Yiyong's own obsessions. He acts as a magnet drawing to him spirits that are yearning for help, and acquaintances that become friends or assistants. He quickly becomes the center of a trio, with a former classmate and a young woman police officer, who quickly finds that she could consider the young men as her own assistants in the investigation of unsolved cases. The three although almost opposed from circumstances of their past and present, become sort of friends, close enough to be a sort of brother-sisterhood that can share views (literally seeing what others can't! ), food, drinks, even a bedside to ward away fears of the unknown. They are friends after a while, although they can be stinging and wound the pride of each other with carelessly flung utterances (especially the policewoman).

They are like pieces of a puzzle, much like the scraps of charred paper that Yiyong collects after his "missions", which connect together to reveal a benevolent meaning. From the start, their names show how much they are fated together like the four "treasures" of the literary Chinese: 《笔、墨、纸、砚》, bǐ, mò, zhǐ, yàn. (brush, ink, paper and stone)

* Pu Yiyong 蒲一永(played by Tseng Jing-hua 曾敬驊 born 1997)
His family name 蒲 immediately reminds of literary connections with ghost story writer Pú Sōnglíng (蒲松齡 1640-1715),
"yi" is "one" as in "the first" and the most important
and "Yǒng" 永 is the well-known "eternity" calligraphic character;
of course Pu Yiyong is a calligrapher, as well as a budding manhua artist, wielding the 笔 bǐ brush (or pen, when used in drawing or ordinary modern writing).

* Chen Chuying 陈楮 楮(played by Vivian Sung Yunhua 宋芸樺 born 1992)
Her name Chén 陈 is shared with Chen Zhonglin also known as Xu Zhonglin ( 陈/许仲琳; 1567 -1620 ) a famous Ming novelist who wrote the fantasy novel Investiture of the Gods , as well as being the birth name Chén Yi 陳禕 of the famous monk Xuanzang玄奘 (so perhaps a roundabout hint to another super-famous trio of quasi supernatural literary characters: monkey king Sun Wukong 孙悟空 ; pig Zhu Bajie 猪八戒; and sand demon Sha Wujing 沙悟淨 who accompany Tang Sanzang 唐三藏/ex Xuanzang Dharma name in the epic Journey To The West)
"Chǔ"楮 is the paper mulberry variety that produces 宣纸 "xuānzhǐ "paper (rice, bamboo have also been used to produce it) used for traditional Chinese calligraphy
"ying" 英 means "heroic", "brave", "brilliant" combined with other Chinese characters: (英雄 yingxiong = hero), (英明 yingming = wise, brilliant)

* Cao GuangYan 曹光研 (played by Peng Cian You 彭千祐 born 1993)
His surname "Cáo" 曹, shared with the famous statesman and general CaoCao (曹操 155-220) can also be found in "yincao" 阴曹= the Netherworld, Hell, Hades;
"guāng"光 means "bright" showing his qualities of clearing up the esoteric murk through a sunny disposition and a rational outlook,
"yàn" 研 is the character in the "yàn tái" 研 台 ink stone on which the ink stick made of ashes is ground in water to make the 墨 mò ink. The character also appears in "Yánjiū yuán" 研究员 ="researcher", or "Yányou" 研 友 other word for classmate (making me chuckle about the memory of the name of the Zodiac snake in the xianxia drama "Ashes of love", but that's an unrelated one).

So, tied together with all these heavily laden symbolic names, the puzzling trio can't help "writing reports" and being instrumental in Pu Yiyong's writing of the magic eulogies that will help seekers find solace and closure for their yearning.

The three young Taiwanese actors, as well as their supporting cast, are excellent in their roles, which are non romantic. One key character in the end of the drama is Chanon Santinatornkul, nicknamed Nonkul or Non, born 1996 in Thailand, who has attained fame in China since 2017.

The CGI is well used and the smokey ghost (seemingly bound by destiny to the Pu family) seen shimmering at the bedside of the granddad, is rather striking, as well as the disintegration and flaking off of some ghostly characters.
The urban landscape is quite typically Taiwanese, and the low furniture, as well as the pronunciation in mandarin (with accent, absence of rolling "erhua" -r finals that are typical of northern and Beijing speech, and shift from zh/ch/sh to z/c/s sounds, influence of the 7 tones Taiwanese, where northern mandarin has only 4 tones ) show the differences with mainland styles.

The drama gives at times the feeling of a stage theater play, with the insistence of the protagonists, the staged appearance of the Doll, the Chinese opera quality of the Tatoo... Is it a tragedy? Is it a comedy? Is it a mystery? All of that, of course: living and dying is putting on a show permanently! First : delineate (make a drawing) of the new characters, next, assemble the clues to recreate the puzzle that they represent...

Music: The opening theme music creates a mysterious and obsessive atmosphere. The end credit song : Painful Hug (痛苦擁抱) by Ozone can be found with subtitles here : https://www.youtube.com/watch?v=-A-z5VWLWsM
The insert song: Extraordinary (不凡) by Chang Ruo Fan (張若凡) can be listened to here: https://www.youtube.com/watch?v=Su_gTQL093o

Will I re-watch ? Most probably, to better appreciate some dialogues and jokes, since there is also a lot of humor in these "distressing" cases of abandonment, harassment and even murder! I am already appreciating the circular movement of time with the first images and the last event.