The Leacher’s Emerald

Its master and wielder, (attuned), can attempt to
magically implant it into the chest of any living
creature. The creature must win a Grappling
contest to be able to resist the attempt. (Bonus
action) The master can use it to transfer 3d6
Hit Points from the victim to them-self if it
is within 60 ft. The emerald has two charges per
day and regains all of its charges at dawn. The
gem exerts no control over the victim otherwise
but every use shifts the master closer to evil.{g}