[@Infamous Empath]

So a few issues. I assume that these will all stem from me not explaining enough in an attempt to leave things open ended. So when the emperor's men captured Daren's loved ones they would almost certainly have been shipped off to Hurica as exiles. The emperor is just doing this to all criminals and political opponents regardless of how good or bad of an idea it may be. So they would not actually have been around to bargain for. In the same vain they probably would not have spent much time torturing him unless he was someone with valuable information or something. Again standard practice is to just exile prisoners and be done with them. If the continent doesn't kill them they will be too far away to do anything. As such they also would not really care to send someone to assassinate someone who they had already exiled. That person would already not be an issue.

So I think there are ways to work with what we have. If his loved ones are the most important part for the character then perhaps he gave himself up as a traitor to the realm just so that he would be sent to Hurica where they were. Perhaps then when he get's there one or both of them are missing.

Alternatively if you were really going for the assassinating a guy angle I can work with that, but it will have to have been something he decided to do on his own accord or perhaps a task given to him by some other organization other than the new empire. Perhaps a thieves guild wants him to punish a traitor for them and he is loyal or personally scorned enough to give up his future to do it.

Obviously use your own details and mix and match things as you wish, but as he is right now he just does not logically fit.