I destroyed my coworkers career because he was trying to get me fired and now I am living his life.

I have been at this firm for three years and I was the go-to person for the legacy codebase until they brought in this new guy six months ago. From week one he started a quiet war against me. He would "review" my merge requests and intentionally introduce logic errors or just flat out delete my comments to make my work look messy. Then he would go to our CTO and mention how I was struggling with the new architecture and maybe I needed a "mentor". He was basically gaslighting the entire team into thinking I was incompetent while he was out there playing the office hero. It was not just about the promotion anymore it was about survival. He was poisoning my reputation every single day and I could see the management starting to pull me off the high-profile projects. About three months ago he was working on this massive database migration that was supposed to be his big win. He was so paranoid about his code being stolen that he kept everything on a private local server instead of using the company git. He thought he was being smart but he was using the same generic admin password that the rest of the dev team used for the sandbox environments. I stayed late one Tuesday when the office was empty and I just felt this wave of pure rage. I logged into his server and I did not just delete the project files. I ran a wipe utility that wrote zeros over the entire drive so there was nothing left to recover. Then I modified the shell history and the access logs to make it look like a system crash or a hardware failure had triggered a data corruption event. It took me fifteen minutes to erase his entire professional existence at this company. The fallout was even more brutal than I expected. When he realized the data was gone he went into a full blown panic. He tried to blame the IT infrastructure but when they looked at the server it just looked like he had failed to set up any redundancy or backups. The CTO was livid because the client was expecting a demo that Friday. They did not just demote him they fired him for gross negligence and for putting company data at risk by keeping it on an unsecured local drive. I stood there and watched him pack his desk while I offered him a "sympathetic" look. I got the lead position a week later because I was the only one left who knew the system well enough to rebuild the migration from scratch. I am sitting in his old office now and I have the title I wanted but the guilt is starting to rot me from the inside out. I found out from a mutual friend that he was actually under a ton of pressure because his visa was tied to this job and now he might have to leave the country because no one will hire him with that kind of termination on his record. He was a jerk and he was definitely trying to sabotage me first but what I did was on a completely different level. I am essentially a criminal who got lucky. I spend my days staring at the monitor and I can not even focus on the code because I keep waiting for some senior admin to find a log I missed or a footprint I left behind. I won the office war but I think I lost my soul in the process. I even started drinking more just to sleep at night without seeing his face when he got the news. The funniest part is the CTO keeps praising my "work ethic" and how reliable I am compared to the last guy. I just nod and thank him while I try not to throw up in the trash can. I have the paycheck and the status but I would give it all back if I could just go back to that Tuesday and just walk out of the building instead of logging into that server. I am just waiting for the other shoe to drop at this point and honestly I probably deserve it. I guess I am just better at being a villain than he was.