I want to cause my future brother-in-law to lose his inheritance.
Why on earth would you think this?
I think there are better ways to use the inheritance.
That money is none of your business and you should leave him  alone. It's not your right to have any say in his financial situation.
Nobody would care if that asshole lost his money.
This man's financial matters and inheritance are not of your concern and you should stay out of it. It's not your inheritance so it ultimately doesn't matter how you feel it would be best used. You should leave it alone and focus on your own personal finances.