A new page appears in your Book of Shadows. With
your permission, a creature can use its action to
write its name on that page, which can contain a
number of names equal to your proficiency bonus.
When any creature whose name is on the page
is reduced to 0 hit points but not killed outright,
the creature magically drops to 1 hit point instead.
Once this magic is triggered, no creature can benefit
from it until you finish a long rest.
As an action, you can magically erase a name on
the page by touching it.