Abusive freeholder who lives in the building. WWYD?

I own a leasehold flat in a victorian conversion in England. There is a flat above me, also leaseholders and a flat on the top floor, who is the freeholder. He was a leaseholder and decided to purchase the freehold from the management company when it was offered and previous leaseholders didn't buy it (apparently). I have my own front door (thank fuck).

The problem is he has severe issues. When I bought the house, he withheld the management pack and delayed the sale by months (I didn't realise he was the one responsible for this until I met him). When I moved in, he asked me repeatedly what I paid and chuckled at the thought of the previous owners losing money. He has tried to hit on me repeatedly - sending me messages saying I'm hot, that he's naked in bed and then constantly asking me for coffee when his wife and kid aren't around. He also tried to get me out on the scaffolding a few times, like literally 'Hey wanna climb out my window and onto the scaffolding with me?' I declined.

I had to tell him to stop taking my parcels if they were they left outside my front door when I wasn't in or just in the garden. He would take them to 'keep them safe' and put them in his car or the hallway of his house. He has fitted a camera in the porch of the building that he said is just recording the front door to the rest of the building but I believe it also captures the whole patio (which I own) and he seems to be aware of things like what time I go the gym in the morning and informing me my builder just stepped in fox poo.

I've observed that whenever the other leaseholder (not in the property, she rents it out) or her tenants challenge him on anything, he has a complete melt down and gets very vindictive. He's pretty much inflicted financial abuse on the other leaseholder by causing a lot of damage to her property when having his flat renovated and if she confronts him on anything, he ends up doing a 'property inspection' and finding something she needs to replace instead, and then uses legal pressure to force her to comply (last time it was replacing her windows). When the tenants asked to have access to the porch camera footage, he became incredibly angry over text and told them they will have to sign an NDA (?) and then threatened them with eviction (which he can't do).

Over Christmas, I noticed one of his workmen had caused some damage to my property when putting up a scaffold (the second time in a year we've had scaffolding for his flat) so I flagged this with him.

I was treated to an entire melt down over text that got incredibly personal and called me a snide bitch and said he wasn't my friend anymore, and ended with a threat of 'Am I going to have to come round and do a property inspection?' which is his code for 'I will come and find an issue that you will end up paying for.'

Basically, he's abusing his power as a freeholder and in my opinion, is guilty of harassment.

My friends have told me to screenshot all old messages and instances where he has made me feel uncomfortable and go to the police. Which I am going to do... Obviously, this is likely to make him worse if they end up speaking to him.

My other thought is to also band together with the other leaseholder and buy him out of our shares of the freehold. I know there are some changes to the leasehold bill coming in 2026, but I'm unclear about what they are and whether i'd just be wasting my money if freeholds & leaseholds get phased out. Buying my share would mean shelving some much needed renovation work tbh. But it's would also reduce him to being an annoying neighbour and co-building owner than someone who could financially cripple me.

TLDR: The freeholder to my building lives in the property and abuses his powers. He also has tried to hit on me repeatedly behind his wife's back. He gets verbally abusive and vindictive when confronted. He's inflicted financial abuse (IMO) on the other leaseholder when they've confronted him. I'm considering whether I and the other leaseholder buy out our share.