Thaumatech from Mages

Obviously, Legacies such as the Daksha and the Legion would have useful monster bits, but what would a mad vivisectionist get from other mages?

Organs saturated with Supernal Energies - perhaps eyes that detect supernatural phenomena, an Obrimos' hand that exerts a lot of force (albeit more than the hunter's body can take without its own damage), a Moros' heart that allows the hunter to pass undetected among the dead, a Mastigo's eye that sees lies.

I think sensory organs would be the most popular bits to lop off mages.