It’s a scam. Do not engage. If a billionaire really wanted to send you money, they can pay for the lawyers and accountants to make sure it is all above board. Maybe thry make a foundation and give you a cushy job there. That’s how actual billionaires do it.

Ironically, if it weren’t a scam, then crypto can be the safest way to receive any funds. If you securely generated your own crypto wallet, and sent him an address on a reputable blockchain to send funds to, and he actually sent them, then the money is yours, forever, no backsies.

Of course, that’s not how crypto scams work, either. They always guide you to use a wallet that they control (and can drain funds out of easily), or tell you to send crypto to them first to unlock something.