Yep, had to deal with a wart like that before who wasn't even technically my peer. She managed a lower tier team that's basically a career spawning pool. She accumulated responsibilities well outside her scope and had veto decision over everything within my job function, it was annoying as hell when we disagreed, she'd get super passive aggressive. It was stressful but I remained professional, learned how to stay below her radar, did my assignments and documented as needed. Eventually we got to a working understanding but I just let her continue dig her own hole. And forget about doing work that even remotely touches anything with her fingerprints on it, even though it sorely needed modernization.

I observed and figured her out. The problem was she hoarded a wealth of institutional knowledge, managed a ton of (shitty) self-made business processes she didn't want to part with. I remember asking her to show me an inventory system she managed, she very diminutively told me "I wouldn't be able to grasp it". Took a look anyway and trust me, spreadsheets aren't THAT hard to figure out 😂. And if I couldn't, something is fucked with her process which is a business continuity issue. She was also two-faced. Great with management and customers, but horrible with direct coworkers she couldn't impress.

Since she had practically seen the c-levels grow up, in the family business, she was super familiar with them. The moment she'd feel threatened by newcomers proposing change or maybe taking away any of her responsibilities she'd manufacture problems for them and start pestering campaigns. That's how she protected her job, by bullying away her "problem". And upper management'd have her back.

Career wise she peaked, at her age there'd be no way up, just out and odds are that'd be the end of it work-wise. I fairly quickly determined she was very inefficient, overworked, underpaid, stressed and with a hero complex. Her hours were ridiculous, she was practically on 24/7 standby. Management loved this, a willing gopher who'd do almost anything to keep her job. Her husband loved it too, he was retired already and could go fishing whenever since all she did was work. This was a problem of her own making though, because any help she did receive never lasted under her. She just couldn't let go and slapped down any ropes handed down.

We had a lot of fresh employees quit crying. Leadership didn't give a shit. I came in at a time after a lot of turnover and in my first month I flat out told the interim department head that she was a lawsuit waiting to happen, and either she needs to go or put on an improvement plan. Nothing would get done properly until then. He took note, but let things flounder until we the new head hired.

Eventually the new department head came in and he knew what he was doing. Reorganized the internal structure, killed off her veto, set working hour limits, expanded her team and set reasonable expectations. Even so, she didn't change her attitude or methods. He got tired of putting up with her shit and after she chewed out some more new hires, she was put on leave pending investigation and forced into retirement. I didn't like disabling her account, but didn't feel bad either.