What kind of an evil dark wizard are you to come up with such torturous techniques!?
Lol but forreal. Mend buttcrack? Lol that's an extremely long and growingly painful death haha. I would never dare get into a magical showdown with you
Flesh to stone on target, then stoneshape their head up their ass, then dispel...
Sure, you could just use one spell to kill your enemy, but for a squishy wizard, forcing someone to watch their friend use their last breath to scream into their own anus about the unimaginable pain of their tortured spine, makes a compelling deterent for further aggression.