This troper declared himself the Arch Enemy of one his supervisors.

This troper had two, during the 6th grade and High School respectively. The first one was this all-around jokey otherwise likable new guy who didn't do anything to me at all. The other one was his exact opposite; an unsavory only-the-strong-survive jerkish outcast with no real friends who happened to be my brother's best friend's brother; for the record, I didn't do anything to him either. Then he volleyed one too many insults; I returned fire. We've since moved on; I made peace with the first dude and we ended up being friends, albeit when we were on the same team in PE class; the other one, well... relatively recently. Funnily enough, neither of them ever met each other, but if they did, I wonder if they'd turn on me or, given their vastly different natures, each other.

This might be the most nonsensical use of potholes on the history of Tvtropes. God help us all.

This troper, ever since she was young, has been arch enemies with the grandson of her uncle (he's not really my uncle). I can't remember why. Every time I see him, the first thing I do is hit him. We're actually on good terms with one another, and have always played with one another. Similarly, in school, there is a boy whose demeanor and "I'm better than you" personality I cannot stand. We're usually on good terms, though.

Edgy here. My most recent arch enemy was my ex-girlfriend, Misty. I helped her cheat on her boyfriend (not proud of that), but she started it by seducing me. We broke after her boyfriend found out. She lied about a lot of things so basically, she painted us each as an abusive rapist to the other. But after I found out about her lying, we were immediately at odds with her boyfriend (now husband) Stephen as her Dragon. Stephen thought I was the bad guy so he tried to antagonize me, I laughed it off. Then, they tried a fake intervention in front of their friends calling me a stalker and such. When given a chance to say my peace, I was silent and walked out. When I started talking to other girls, Misty tried spreading rumors but no one believe her. When I got a girlfriend (now my wife), Misty called me a rapist. When I got engaged, Misty and Stephen made idle death threats. I managed to out gambit her everytime. In the end, she was left with no friends and a tool bag of a husband. She's no threat to me now and I see her once a year at an anime con.

In elementary school one of my classmates was my Archenemy. She always tried to one up me in school and when that didn't work she resorted to making a larger friend group than I. When we weren't competing academically or socially she and I always tried to beat one another in sports.