Had one of those at my former workplace - referred to them as the ButtKisser (BK). While they were completely competent at their job, instead of just working hard and being nice to everyone and climbing up the ladder through being a badass, they still felt the need to suck up constantly (to the point of nausea for those of us witnessing the actions). BK made it a point to denigrate peers they saw as a threat as well, so not only did the boss feel like this person was their bestest friend (and started hanging out together socially as well), they felt like the rest of the department was against the boss, and hated them - so it was a masterful move to both become the boss' can't-live-without worker, they also made sure that no one else could get close or would be trusted by the boss in any case so they were the one to reward or deny other workers as they saw fit.
Fun thing was, eventually when BK was firmly ensconced in the number 2 position, BK started a smear campaign against boss with higher ups, then took over the department, and the former boss was regulated to a secondary position with less authority. And it was all thanks to BK's subtle campaign to make boss look incompetent every chance BK got. In every meeting - where boss person wasn't attending since that was one of the delegated tasks for BK to handle - there was at least one dig about how boss didn't know how to use "standard program" or wasn't capable of understanding so BK would have to take on that project themselves to ensure it would be done correctly. So not only did boss end up being isolated and hated by their own department, they were eventually seen as a helpless airhead throughout the company.
I personally gave up advancing myself because I wasn't willing to go to the extremes of sucking up that BK was, and frankly I didn't want to do boss's work in addition to my own (which is what happened for close to a year before BK was rewarded with perks). But I also was targeted (like several other coworkers), by BK until BK realized we weren't interested in competing with them. It sucked for a very, very long time. But I was around 3 years away from retiring completely and I had no place that I could have moved to that would not have been a big step backwards at the point in time that made no sense... so I put my head down, did my work and tried to ignore the stupid shit as best I could.
SOOOOO. The TL/DR version of the above? These types of people pop up now and again, and they are never someone you want anything to do with because they are out to climb to the top of the ladder, and will do so gleefully over your body if you get in the way (or are perceived to be a threat). And it sounds like your BK is definitely gunning for you. So the best thing I'd suggest is either fight back by being super productive and start your own sucking up (as much as you can anyway), or start looking for a transfer within the company if possible or new job elsewhere. Because unless you can out-kiss this kissass, you're likely going to continue to have your work nitpicked, every little thing you do placed under a microscope and basic bullying becoming commonplace (and your bosses sound like my former boss - stupid and easily manipulated if they get their ego stroked by the BKs out there).