The Oracle's Couplings (CoS Zone)  

Type	Rec Level	Rec Power (Heroic)	Common Mobs	Bosses	Quests	Dungeon Objectives	Vanquish
							Common Drops	Rare Drops
The Oracle's Couplings					Accessible from: Founders' Annex
	42+		Mechanthrope Brain Mechanthrope Brain Mechanthrope Butcher Mechanthrope Talon Trow Elder Trow Faerie Trow Sapling Trow Thorn	Rootcaller (42) Tyrant (42)	The Mysterious Sphere	1960 1405   Kill Rootcaller and Tyrant
The Oracle's Couplings					Accessible from: Founders' Annex
	45+		Mechanthrope Talon Risen Axiom Risen Brute Risen Eye Risen Sentinel	Gatekeeper (45)	A Gate with Destiny	1950 1395   Kill Gatekeeper
Notes: The boss spawns when you kill the last group before the final room.
The Supply Tunnel					Accessible from: The Oracle's Couplings
	46+		Mechanthrope Talon Risen Axiom Risen Brute Risen Eye Risen Sentinel		[Optional] Bring Home the Beacon	14700 5035
Oracle's Coupling 1 Boss Raid
	45+	47112 (68594)	Risen Axiom Risen Brute Risen Eye Triggershade Imp	Magister (45)	[Vanquisher] Re-Coupling [Challenge] Heroic - Re-Coupling	Kill Magister	8658 5806 11 3	Weapon, Shield
Notes: a.k.a. Oracle's Coupling Slayer
Oracle's Coupling 2 Boss Raid
	47+	52215 (76373)	Trow Elder Trow Faerie Trow Sapling Trow Slate Beast Trow Thorn	Blackthorn (47)	[Vanquisher] Oracle's Coupling Boss Raid [Challenge] Heroic - Oracle's Coupling Boss Raid	Kill Blackthorn	9207 5786 12 4	Armor

City of Steam Wikibase™ Zones

Each Boss Raid Challenge dungeon that you complete will grant rewards in addition to any items you find within it.

• Normal mode: Transmuter Orbs, Mastery Points, Expertise Points, Rare Materials Boxes, EXP
• Vanquish mode: EXP, Shillings, Mastery Points, Expertise Points. Note that EXP is higher than Normal mode to compensate for the loss of kill EXP that you do not get in this mode.
• Heroic mode: Rare Materials Boxes, Orange Material, Shillings

In Oracle's Coupling 2 Boss Raid, Blackthorn does not appear until you engage the first of the common mobs that are right in front of him.