Just as when the credits roll and you are asked to save a clear data prior to the final boss fight, not everything about the game ends. In fact, you may continue to work on your kingdom and recruit a few more citizens that can only be recruited after finishing the game and having that clear data on your save file.
Among the citizens that you can recruit for your kingdom is Senturi.
How to recruit Senturi
As soon as you load that cleared saved game data and you find yourself just before the final boss fight, go back to Evermore and check Senturi just at the gate of your kingdom. Senturi appears randomly on your castle so if she’s not there, I advise you to check regularly.
Senturi will ask you to kill a Tainted Monster in the Drylands. Hop aboard your Zepplin and head to the Shrine just at the tip of the Drylands.
Once inside the Shrine, go to the marker on your map and find the tainted monster that Senturi wants you to kill. Please note that the recommended level to defeat this boss is at least Level 65. If you are no way near to that level, I suggest to do this one later and level up your characters.