A person who is legally responsible for the person or property of another considered by law to be incompetent to manage his or her affairs
Liz, I think you have a keeper here.
"I'm definitely not his keeper," Sofia said with a shrug.
Euphorion was made keeper of the library at Antioch.
The keeper of ancient Immortal histories, Tamer was able to read scripts from the time-before-time.
Soul collector, grim reaper, death-dealer, assassin, Keeper of Souls.