Here is the full list of all 10 Fateful Mages achievements.
Reset character progress once.
View credits.
Decide fate for all 28 characters.
Decide fate for 24 characters.
Decide fate for 20 characters.
Decide fate for 16 characters.
Decide fate for 12 characters.
Decide fate for 8 characters.
Decide fate for 4 characters.
Decide any character's fate.