In principle and based on my personal experience, it is possible to rent your brother's house, get him to sign your registration form from the residence office, and then obtain a tax number. It takes 1-2 months to arrange, and you need to be present.
Then you wait 12 months and
cash out your
cryptocurrencies, wait an additional 6 months, then deregister from Germany and report that you have moved to Brazil. They do not check it. And your cryptocurrencies are out. I carried out this strategy 2 years ago. I received a letter from the German tax authorities, told them I live at an unknown address in Brazil, and have not heard from them since.