My DP's brother is the biggest narc I've had the displeasure of knowing, I could write a book about him! He lives in Oz so thankfully the times we've actually had to spend any time around him have been few and far between.
First time I met him he was over visiting and staying with the oldest brother, he kepy phoning my DP (youngest brother) and making all kinds of ridiculous demands such as being taken to McDonalds at 1am or phoning at 4.30pm demanding to be taken to a gift shop at Hadrians Wall which was about an hours drive away and throwing an epic tantrum when DP said shop would be closed by the time they got there. Best part was DP didn't even own a car, I did, and his brother just made the assumption that what was mine was DP's and by extension his!
Then he announced he and his partner were getting married in Crete and he wanted DP as his best man. The next year was an endless barrage of ridiculous demands. They wanted the oldest brothers daughter as their bridesmaid, however they didn't want his partners children there until the older brother basically said "well I'm not coming then". Constant demands from him in Australia to my DP to go here there and everywhere to do this and get that for him in the UK.
When we all arrive in Crete for the wedding narc brother collected us from the airport and took us back to the apartments they had rented out for their family. The brides family are Greek and speak no English, they forced us all after almost 24hrs of travel to spend the night "socialising" with her family and would not let any of us go to bed. He kept trying to force us to eat ALL the food the Greek family had brought or "THEY WILL BE OFFENDED!". The rest of our time there we had to jump every time he clicked his fingers lest the Greek family got offended. His demands included that me and DP went to town right away to fetch medication for brides sister, RIGHT NOW, I'M NOT ASKING I'M TELLING". Any time anybody tried to go anywhere without his permission he kicked off, once following us down to the beach and squaring up to both of his brothers trying to start a punch up. He demanded that his brothers HAD to perform a stupid fucking dance with the bridesmaids at the wedding (DP has arthritis in his knees and flat feet!) or they'd be RUINING his wedding. He demanded the night before the ceremony that I had to drive one of the cars ferrying family members to and from the wedding. I didn't want to, had not driven a car with everything on the wrong side and on the wrong side of the road before and was quite frankly terrified, but he bullied me into it by screaming in my face that I'd be RUINING his wedding by refusing to comply.
On the day itself he turfed his aunt and cousin out of their ground floor apartment as he decided that's the room he wanted for he and his groomsmen to get ready. They took so long that they only left about 10 minutes for his aunt and cousin to get ready, they didn't even have time to do their hair or make-up and were inevitably late getting going, I was the one driving them and he was calling me every 5 minutes screaming down the phone at me that I HAD to get them in the car right NOW, I was RUINING his wedding. Eventually his other aunt took the phone off of me and told him to stop bullying me.
He and his wife behaved appallingly to his family and hers to the point nobody was speaking to them after the wedding, we actually did spend a fair amount of time getting to know the brides family despite the language barrier, turns out they weren't at all offended by anything any of us had done and were shocked and horrified that he had been saying that about them.
Most recently he came back to the UK and noticed for the first time that his mother was potentially suffering with dementia and took it upon himself to swoop in like some kind of saviour and "saving her" which looked like him taking her pension and buying a load of ready meals from M&S (mostly for himself) literally force-feeding her, installing cameras around her house so that he could sit in Australia watching his oldest brother and his mothers neighbour caring for her and then phoning on a daily basis to scream abuse at them about how everything they were doing was wrong. He forced his mother to allow him control of her bank account and then when he got back to Oz he blocked her from being able to use it, her neighbour was trying to get her shopping for her and he'd cancelled the bloody card!
Then she died, he came back for the funeral and blamed his older brother and the neighbour for her death. They had literally spent years looking after here, tying themselves up in knots trying to get support in place for her etc while he was barely involved, he never even sent his own mother birthday cards or called unless he wanted something.
Lastly he tried to get my DP to start sending medication to him in Oz, making promises of training my DP to work with him in his field and making lots of money. DP has autism and can be naive, me and my dad had to tell him he might potentially find himself in hot water sending all those pills to Oz. Brother was furious with me for meddling and immediately withdrew any offers of work/support for his brother until he stepped into line and did as he wanted. Now he is terribly shocked and saddened that his little brother is completely done with him - all my fault apparently!