Paws's Questions (3)

So.. I know the plot a bit and even what the main dude looked like but I really cant remember the name.

It is a manga, about this serial killer killing people without ever even touching them, he kills them by using placebo's. The MC dude is the killer who usually wears red and/or a black suit with a red tie. There's someone who has been trying to catch him, I'm not sure if it's a dude bcs my mind is saying it's a police woman but also not? I think it has an live adaptation where the one who's chasing him is a girl but in the manga it's a guy. Not sure. But he's a killer who uses placebo's to kill.

I've been trying to find it for a while now but whenever I search up placebo killer, that damned bl manwha keeps showing up..

I don't know specifically if it was a manhua or manwha but I do remember that it was about martial arts! The mc time traveled/regressed, though I'm not sure but he can input real money into this screen thingy of his and that screen gives him stuff that makes him stronger. The first chapter was about his family not agreeing with letting him be a martial artist because they weren't that well off, I think.. Please help!!

I've been trying to find this specific manwha (?)
Honestly I'm not sure if it was even Korean originated but it's a bl where the mc probably has white hair and created a world but lost his memories and he meets a big guy with black hair who takes care of him