I like horology.

Steal Youth -8th circle, horology.

When cast, the steal youth spell causes one creature to instantly age 4d6 years, and another to grow the same number of years younger. A successful fortitude check reduces the years stolen 2d6 years. Furthermore, if the recipient to grow younger resists, the years stolen are reduced by half once again. For example, if both creatures resist successfully, 1d6 years are transferred. If one creature resists, 2d6 years are transferred.

Undead and extraplanar creatures are unaffected by the steal youth spell.

Note: If the steal youth spell results in a creature passing its minimum natural life expectancy, the Game Master will determine if death due to aging occurs. For example, if a dwarven character were more than 150 years old after a steal youth spell, death may occur. Similarly, if steal youth reduces a character to less than 0 years of age, the character dies.