Game version: 0.4.48b 64bit
Windows 10 - 64bit
Using spells on a slave breaks the system, and trying to use a spell on an other slave won't work and will instead target the first slave.
For example: I have a human and an elf, I cast mind reading on the human: it shows her stats; I then cast mind reading on the elf: it shows the human's stats.
Also trying to use mind reading after finishing the quest will instead show the stats of the slave that was traded.

On the screen, " Laurine " is the name of the slave I gave to the mage recruiter dude, and you can see on the right that I selected " Anissa " and don't even have a " Laurine " in the list.
The only way I found to change the target of the spell is to use it outside of the mansion.
And it will stay locked on the new target when you go home anyway.