'whoops' I wiped out 80% of the active db (2019 Jan-May). Anything purged before early May is lost... (details)
Today's trope is Your Soul is Mine. Here is the link: https://tvtropes.org/pmwiki/pmwiki.php/Main/YourSoulIsminePeople just can't seem to get enough of them souls! "Purchasing one legally" is only one method of obtaining them. Outright theft works just as well, with much less hassle.
There's a few ways it can go:
Just the Soul The soul is "merely" eaten or taken, but the person's body is still alive. Often, the monster will gain power from this, while the victim turns into an Empty Shell. Recovery is sometimes possible, sometimes not.
Killed Too The soul is stolen or eaten, and the person is killed in the process. If resurrection is possible, they nearly always Come Back Wrong thanks to this, since the soul is most definitely not where it belongs. Often, this is exactly what the villain wants "Steal people's souls and kill them, then resurrect them as an immortal army." If resurrection is impossible, then the person is probably Deader Than Dead. In a Nobody Can Die setting, this may be reduced to "loses consciousness, and is slowly dying unless the soul can be recovered." Recovery here is possible, but with a definite sense of urgency.
Drained After Death The soul is stolen or eaten after the victim is killed by other means. Though it tends to play out similarly to Killed Too from here, this is commonly used by Amalgams Of Souls to increase their power.
TL,DR: A character, item or ability that steals other people's souls.
Shang Tsung (Mortal Kombat)
Maximillian Pegasus (Yu-Gi-Oh!)
Dementor's Kiss (Harry Potter)