How do I include my little brother with Down Syndrome in my wedding

Im getting married in 2027, and asking all my sisters to be bridesmaids. I have an 18 year old brother who has down syndrome who I want to include. I know someone will say "what does he want to do?"- well what he would want is to break dance in front of everyone for the whole time and make diss tracks about the entire guest list.

So I want some fun ideas... not just a greeter or a ring bearer. Something fun where he would actually enjoy it. I was thinking something along the lines of announcing the wedding party walking in. I was also thinking about getting him a chain (because he loves huge rapper chains) but idk what that would be.

I'm not looking for anything like normal I guess, something fun that is uniquely him.