Life Force allows the user to double their life span, causing them to age at a slower rate, making them look much younger than they really are. This is why Kyudai Garaki looks as if he's only in his sixties when he really is at least 120 years old. If the Quirk is cancelled, the user rapidly ages into a much more decrepit shape.
At some point, Kyudai duplicated his own Quirk and presented the original to All For One as an offering while he kept the duplicate to himself.
This Quirk comes at the cost of sacrificing physical mobility. However, All For One appears to have managed to circumvent this weakness through the use of multiple other Quirks.
- Life Force, All For One, One For All, Fa Jin, and the unnamed Luminescence Quirk are the oldest known Quirks in the series.