A weird hypothetical I came up with at dinner.
You have the power to drain youth from others. All you have to do is look at a person in person (i.e. no video or photos), and think, with intent, “Drain.” That person’s body will age by 24 hours, and yours will get younger by 24 hours. This is instantaneous, has no other effect or feeling, and only needs you to see the other person — so you could do this to people who drive by you on the freeway, as long as the other vehicle’s windows aren’t tinted. The effects stack, so draining from 365 people in this way in a single day would make your body a year younger.
For the purposes of this hypothetical, the future is indeterminate, so you are not necessarily and directly causing the other person to die 24 hours sooner than they “would have.” Further, this effect affects temporal age only — cancer in the other person doesn’t grow 24 hours bigger, for example. Similarly, while your hair would get 24 hours darker and your wrinkles 24 hours tighter, your own cancer wouldn’t get 24 hours smaller. So, assuming no disease or accident, you could do this just once a day to “freeze” your body at the physical age you were when you started using this power. (Yes, there are unanswered questions that this raises, but I hope my intent is clear.)
You can never drain more than 24 hours from a single individual in this way, no matter what, so if you accidentally pull this on the same stranger twice, nothing would happen, no matter how much time has passed.
So would you use this power at all? If so, how often?