This is tied to side quest:
FreedmanTo unlock this side quest and achieve the achievement you need to first save
Coty who is a slave being offered in slave auction by
Parsim Flint in
Memovira's Courtyard Map in
Bloom.
You find
Parsim Flint standing on a podium near a pit protected by energy field where slaves are being offered. You can buy
Coty from him (400 shins or 300 if you'll pass the negotiations).
After your purchase he will appear standing between green Obelisk and slave auction in
Memovira's Courtyard Map in
Bloom.
You can then begin side quest:
Freedman1) Ask
Coty that you want to free him and that you will find a suitable job for him.
2) One of the jobs on offer is a guard for Memovira which can be talked about with
Brusca, it's main guard standing in front of the Gate in
Memovira's Courtyard Map in
Bloom.
3) You will need to first purchase necessary equipment for Coty which Brusca demands - it will cost you 300 shins.
4) Then you also need to further persuade her to took him in.
5) This side quest is then finished
So back to the achievement - after you complete the task for
Memovira to find and free scholar
Ishen from main quest:
Into the Depths. This quest will continue with meeting her again in
Memovira's Fortress. When you choose to kill her after discussion about activating resonance chamber,
Coty will be standing near
Mazzof, fighting on your side and the achievement will pop-up.
PS:
Coty is a pretty useful character after you purchase him. You can ask him to steal something for you (shins, items).
*** Spoiler - click to reveal ***You can also offer him to maw after finding out that he accidentally killed his sister.
You can try to offer him to Decanted, alien being appears in Memovira's Courtyard Map later on, tied to Preservation of Beauty side quest.