Ktjn is a Viera who can be found in the town of Rabanastre. The side quest involves speaking to her a number of times throughout the game and, depending on how you answer, she rewards you with an item at the conclusion of the quest.
The first time that you can speak to Ktjn is after the conclusion of the events in the Barheim Passage where you rescue Basch fon Ronsenberg. Ktjn is located in the Muthru Bazaar area and can be found in a little crevice in the stairwell. Use the screenshot below to help you find her.
As mentioned above, the first time you can speak to her is after you have completed the Barheim Passage dungeon. The walkthrough and strategy guide section mentions each of the times that you can speak to her and how to answer as different parts of the quest become available, but the full list is included below.
Question 1 – after completing the Barheim Passage:
But the land, I cannot hear it… Should this not trouble me as a Viera?
Question 2 – after the events aboard the Dreadnought Leviathan:
I knew my choice would bring hardship, yet…
Question 3 – after the events at the Tomb of King Raithwall:
Do you think it possible?
Question 4 – after you have reached Mt Bur-Omisace for the first time:
What do you think?
If you missed one of the questions, you will receive a new question every 15 minutes after you reach the Sun-Cryst.
Return to Ktjn after defeating Judge Bergan at Mt Bur-Omisace to conclude the side quest. Ktjn will make her decision and, although she doesn’t say so explicitly, she will be traveling to the Clan Hall.
Go to the Clan Hall and speak with her (in the center of the room) to receive your reward.
The rewards that you can receive are as follows:
4 points
Location: Inside the Clan Hall
Reward: Platinum Sword (or Runeblade in the International Zodiac Job System version)
3 points
Location: Just outside of the Clan Hall
Reward: Paramina Crossbow (or Hunting Crossbow in the International Zodiac Job System version)
2 points, 1 point, 0 points, -1 point or -2 points
Location: Randomly around Rabanastre
Reward: Ether and two Hi-Potions
-3 points
Location: Outside Migelo’s shop
Reward: Fuzzy Miter
-4 points
Location: Inside Migelo’s shop
Reward: Firefly
This concludes the Ktjn side quest.