Delangue's (Art) Q

If you followed the Casino Rei Long-Oak Quest walkthrough! 
You should have all 10 Paintings
THE PAINTINGS AND LOCATIONS
Four are in the hands of two adventurers (Jane and Sifael). You get each one after you defeat the two in combat, and each time the battle is more difficult than before.
The first time find them at the very start of the game (in the deserted shoreline). Where the Divines lands after defeating or escaping the ghosts/Demon.
The second time they can be found in Fuar. head north then west, just before the Spa..
The third time you find them in a hole in the ground. Go to the desert north of Rei-Long Oak and look for the hole north of the town exit. Note: There are some minor bugs with the third encounter, but nothing game-breaking.
The fourth and final time you find them is in your Castle. As you walk in go to your left, in that small room, and you will see them. You don't have to fight them this time around.
FOR THE OTHER PAINTINGS................. These are in random order, but will give you the required 10 to move on in this quest line. 
(5) Ceeves Ocean: is in the Church section of the Capital. Down from the church. Talk to a Noble Woman wearing very extravagant clothing you'll have to pay out 20,000 for the painting.
(6) Ceeves Ocean: The houses to the left of the Church, you want to walk into the house in the Middle!
(7) Ceeves Ocean: Queens Castle: Go into the basement, once there go inside the gated area and search around.
(8) Ceeves Ocean (Noble District) Talk to the Maid, leave the boat dock and head right (west). The Leonell's (Mansion) however you will need to complete a quest Leonell wants the Heir of the Silverreed for the Painting.
(9) Rei Long Oak: You'll find a bandit wondering around, she will approach the Divine about a painting he may be interested in.
(10) Everlight: GO to the Mayors home and search the first floor the painting is hanging on a wall in front of the entrance door, look at it then ask the Mayor about having it.
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At some point during your collecting of these you should return to the Queens Castle (Ceeves Ocean) after you walk thru the door you should walk around and you should get an automatic dialog as the Divine unknowingly hears a conversation about Delangue, this will give you some information about her (little) you will find out the identity of her.
At some point (unknown what or how) you should take a walk outside the Divines castle (Divine Island) Go south to the next scene, the go west (right) to the next scene, head northwest (next scene) head as far north as you can, look to the east (left) of that area, you should see 2 chests one Blue, and one Red. The Blue one is a mimic (Ancient Armor) the Red one has a few Shade ores.
Go back to the Divines castle once you enter the Castle your assistant will approach you and  inform you about Delangue 'leavaing the castle, and will not be joining you for dinner' (?) but Siné and her sister Jane are in the guest room awaiting you.