To me MBS resembles longest reigning mogul Emperor Aurangzeb Alamgir of India who ruled for fifty years.
He was ruthless with the family, jailed his father Emperor Shah Jahan in a palace of course, killed his brothers, beheaded his elder brother Darushiko and sent his head to dad.
De-eyed his another brother Murad.
Ruled for 50 years.
MBS performed similar right in beginning, jailed cousins and brothers, shaked them well, isolated ailing father and has plans to rule 50 years since he is just 32.
Pretty sure about his max age.
With the blessing of uncle Sam he might do well, for now.
The only difference I could see is that former was a mullah and later is an anti- mullah.
But extremism in both kind is again a common factor here.