I would turn him into a Donkey that has little to no resemblance to his original self (even in terms of personality/cognitive abilities before selling him as a punishment (to have him see the consequences to what he has done) for 50 years.

GIVE THAT PRICK A TASTE OF HIS OWN MEDICINE

Execute him by electric chair.

Send him to the dark web

Or just simple

Send him to Gulag!

Give him a taste of his own medicine, turn him into a donkey and sell him for millions of dollars to either to a diamond mine or coal mine.

Skinn alive then boil him alive

Sentence him with a guliontine

Also put loud music to destroy his eardrums