The power of the Grand Duke was limited
A law restricting the rights of the Grand Duke was passed almost unanimously by the Chamber of Deputies. 57 deputies voted in favor of the law, with three abstentions. Now the monarch will no longer be able to administer justice on his own.
In other words, the Grand Duke will no longer have the right to pardon (droit de grâce), sentence or change the decision of the court on his own. Now such things must be coordinated with the Ministry of Justice and the Public Prosecutor's Office. After that, the Commission de Grâce will make a decision.
It should be noted that last year 250 petitions for pardon were received. 90% of them were for the return of the driving license. Very few were accepted. The Grand Duke's decision cannot be appealed and it's impossible to apply for a second pardon.