From Edge of Darkness Wiki
The changeling ages backward instead of forward: a 50-year-old man gets younger by the day — one year of life is equal to one year reversed (instead of turning 51, he turns 49 on his birthday). This has little mechanical effect, though certainly it’s possible that a player will seek to affect stats accordingly as a character grows younger — Willpower might drop, for instance, but Physical stats might increase a bit. (Why is this such a low-dot Merit? Ultimately, because in the day-to-day game, it doesn’t have a lot of effect.