What is the ruling on making up prayers and fasts missed over eight years due to ignorance of the obligation of performing ghusl after masturbation, given the attempt to make them up but without being able to, and having reviewed various fatwas regarding expiation and making up for the ignorant?

If you engaged in masturbation out of ignorance of its prohibition, then there is no sin upon you, Allah willing. You are not required to make up the fasting days in Ramadan during which this occurred, as long as you were ignorant. As for the prayers, the opinion that they should be made up is more cautious and absolves one of responsibility. You should determine which prayers you performed without ghusl, then make them up immediately in a manner that does not harm your body or livelihood. Maliki jurists are of the view that it is sufficient to make up two days' prayers in one day.