Talk to Jedediah with both of the prerequisite quest items (a Drudanae and the Chalice of the Dragon) in your inventory, then open the hatch to enter Orobas Crypt. Loot the chest near the entry and note its contents. Continue exploring the crypt, and you will find Orobas' remains. Grab the Dragon Skill Book on the ground at the far end (past Orobas' chest).
It may be wise to quicksave before attempting to open Orobas' chest. When you do so, it begins to speak, then briefly display a scene (you need to pay attention to the candles and skulls). It asks three memory questions and you only have one opportunity to answer all three correctly.
|“||Welcome, weary traveller! Within me are hidden many rousing treasures. But before you may penetrate my inmost parts, first you must play. Seduce me by proving the... strength of your memory, the... length of your recollection, the... potency of your mind.||”|
– Orobas' Chest, Divinity II: Ego Draconis
|Spoiler: Orobas' Chest Answers|
The chest contains a Crystal Dragon Helmet, another Dragon Skill Book, and other loot (including elder-level items). Return to Jedediah and inform him that Orobas is no more. Initially the worshipers panic, but soon after you are proclaimed the castle's new lord.
This ends the quest. You receive your rewards and Artemas lowers his prices, however your work is not over yet.
Five ex-Dragon Slayers will reveal themselves to have been working undercover at the castle, hoping to slaughter Orobas. Together the "Dragon Terror Patrol" (consisting of Brethar, Klet, Markthum, Tibus, and Tobelisk) form a much more formidable team than their comical and inarticulate manner might suggest. They are all around level 23, include melee, magic, and ranged fighters, and are in possession of an object that prevents you from using your dragon form. They drop a variety of loot when killed, including the Scorpion Helmet from the Scorpion armor set.
One method to prevent being overwhelmed by the Dragon Slayers is to run to just outside the fort wall where they won't pursue you. From this point, pick them off one by one and retreat back behind the wall to heal as necessary.
- 6000 exp and 1000 gold
- Two choices of: 3000 exp, 500 gold, 1 armor / jewelry / weapon, 1 creature part, 1 gem, 10 herbs, 5 ore, 3 potions
- The manner in which the five ex-Dragon Slayers introduce themselves before combat is a reference to Mighty Morphin Power Rangers.
- And/or possibly a reference to "The Ginyu Force" from "Dragon Ball Z", another group inspired by Japanese Super Sentai groups.