maybe the ML was the guy who killed him over and over again?? the one that he bit in the last chapters?? its really unclear. also, why did he end up turning into a zombie king at the end? I don't get it...

Everyone, and I mean literally everyone is a face con for MC.

Arc 1: Short-Lived Rich Second Generation

Zhao Ming Yang (MC) - Mr. Perfect, Second generation rich heir
Cheng Jun (Original Protagonist) - st**pid, reborn, harem protagonist with a system
Mu Cheng Feng (ML not) - financial group heir, and ability user of a secret organization, feeds MC a pill that shaves off a large part of his life
Du Zi Ran (Original FL #1) - Spoiled school Flower, who still held the original good's in her heart despite saying yes to the protagonist's advances
Zhang Yue (Original FL #2) - rich woman, transmigrated demonic cultivator
100% but only survives about 2 years after eating the pill.

Arc 2: Short-lived Prisoner

Duan Xi (MC) - graduating university student, a prisoner sentenced 4 after being involved in a homicide
Deng Yidi (MC's cellmate) - a curly-haired little brother, MC saves him once in the beginning, is left behind when they're escaping, and ends up fu**ing killing MC a the end
Dyson (Original Protagonist) - forced by the original shou, but ends up falling for him, then starts to take it out on the original goods when he finds out he's a replacement
Wu Ye (Original shou) - behind-the-scenes prison overlord, original good's ex
Wang Hongyi (ML not) - an important big boss in the story, protects MC secretly after they escape from the prison.
Ba Zi (MC's other cellmate) - a tall and thin young man
R (MC's new cellmate) - Japanese man (?), Wang Hongyi's person
Failed Mission, after Deng Yidi goes yande-bonkers and burns them both into flames.

Arc 3: Short-lived ghost catcher

The rules are revised after his failure in the previous world and punishment
Fang Chao (MC) - exorcist, a young master of an exorcist family
Fang Cang (Original Protagonist) - the second young master of an exorcist family, MC's younger brother
Tang Feifei (Original FL) - silly and sweet, a little st**pid heroine, she's not really that important.
Murong Yuqian (MC's bound spirit) - the ghost of a modern man, killed by a chandelier during cosplay as a scholar, he's battle-fighting scum, I think he can also essentially be considered a not ML too
Tang Shangren (ML not) - heroine's brother, has the unfortune of getting involved with ghosts, and is saved by MC who proceeds to kiss him (there's a reason I swear! It's not because he falls for him or anything! You must not be fooled)
After completing the mission, he climbs to the top in this one.

Arc 1: Mu Cheng Feng regretting having fed MC that pill and getting obsessed with him, but then being reborn and finding out somehow that he's already missed MC

Arc 2: Wang Hongyi background protection of MC after they leave the prison and him seeing MC's burnt corpose.

Arc 3: This is the first one where it's not directly about the ML not. It's about MC becoming a legend, takes place after he dies (I think?), and is a grandpa, its a little ancestor receiving his knife (spiritual weapon kind of thing) from (what I assume is) Murong Yuqian.