The Cult of the Sky

The Cult of the Sky is a quest in the Mark of the Assassin DLC for Dragon Age II.
== Acquisition ==
The quest is obtained from a lost scholar at the southernmost point of the Hunting Grounds - West, past a clearing with three ghast nests.
== Walkthrough ==
The scholar has been researching the Cult of the Sky, and explains that one of their altars is in the area. He asks you to take up the search and hands you his notes.
After speaking to the scholar, a plot point appears on the map leading to the altar. Interacting with it reveals a chest with treasure inside. There are two possibilities:
*Taking the loot but leaving the Book of the Lady will allow you to finish the quest without initiating combat.
*Taking the Book of the Lady causes the entrance to the area to seal and initiates combat with a sky horror and various cultists. This route grants the most XP and loot.
Once you have defeated all enemies, interacting with the altar again will allow you to take the Cult's treasure.
== Strategy ==
The Sky Horror is a Boss-ranked Arcane Horror by a different name, and carries the corresponding resistances. The fight is one of the most challenging in Dragon Age II, particularly on Nightmare difficulty.
While fighting it, Cultists will emerge from shadowy portals on the sides to aid it. After it loses 1/4 of its health, it immediately teleports to safety, leaving you to fight even more Cultists including an Assassin.
The Sky Horror uses two spells that deal massive area damage around it, one of which has a very small casting time. Therefore, using melee characters against it is not recommended without preparation.
One strategy against the sky horror involves the typical kiting/barraging, but with a slight twist. This procedure is recommended because its massive health bar, in combination with lethal spells as a caster/destroyer, makes the fight punishing and unusually lengthy.
Because of its rank, the Sky Horror is very resilient, nigh-impervious to even the most forceful/impacting/debilitating attacks. As a result, conventional controlling strategies have little effect, and the Sky Horror will unload area wide spirit spells. Even a Rune of Spirit Warding, reducing this damage by 90 percent, will be little comfort.
With the effects of this high damage + high health combination known, a straightforward strategy can be prescribed:
* Stand around its re-entry point (altar or right in front of the barrier) to bait the Sky Horror into casting the self-centered circular AoE, which has relatively limited range compared to the Entropic Cloud-esque purple attack. Command the team to move out of range as soon as the Sky Horror re-appears at that point, the Sky Horror will conclude that it has no need to tele-port away and commence the ice field channel. As it will not cease the channeling for several seconds, your out-of-range ranged team can rain upon the Sky Horror with impunity while melee characters pummel the cultists.
* If the player has The Black Emporium DLC, they may use dog to attack the Sky Horror and force it to start channelling it spell. Ending the sustained talent early, rather than letting Dog die, to initiate the cooldown may be preferable after the channel starts.
* Dispel Magic is a very useful spell in this encounter. You can use it to interrupt any spell the sky horror is casting. The spell has a very short cooldown so with a little planing every second aoe spell can be interrupted. When upgraded to Transmutation, it can even heal some of the damage the attack caused.
* Careful usage of the fully upgraded Assassinate skill can deal enough damage to initiate the next phase immediately. As a Boss-rank the horror cannot suffer more than 20% of its health in damage from any single hit, but dual-dagger talents count as two hits, extending this to 40% provided each hit is damaging enough on its own. In more practical settings it will average about 20-30% in total. Disabling tactics and spreading the party is nevertheless essential for survival. One can, put the party members on "Passive" or "Ranged" behavior and kite the last mob of each phase until Assassinate is recharged and use it again immediately to initate the next phase. Alternatively, use Tallis's fully upgraded Drop Dead or Twin Fangs with two or more rogues, Tallis being one of them.
* If you position them right infront of the force field, they can instantly hit it with their burst talents again and force it to teleport to safety before it can finish using the ice field attack. Warning : The sky horror will still continue to use its AoEs after teleporting, and it may hit your party if they are too close to the force field. If necessary, use the tank to keep one trash mob alive to buy time for fully cool down the burst talents before the sky horror starts the next phase. 
* It is pointless to try and dodge the swirling vortex attack, as it does sufficient damage to one shot any non tank character before you can move out of the AoE. It is spirit element, thus only a Rune of Spirit Warding will adequately resist it, as ordinary damage resistances, including Tallis's Cloak talent, are only half as effective. The best way to counter this talent is to press the horror enough that it defaults to its localized white AoE attack instead, or to use Mythal's Favor.
* The sky horror is weak to Frost and Nature. It is immune to Spirit, however, so keep this in mind as you plan your elements. 
* This method was tested on Nightmare: Bring a mage with Winter Blast and Vulnerability Hex, a rogue with Brand and fully upgrade Tallis's Drop Dead talent so it does bonus damage to Brittle targets and fade creatures. As soon as the battle starts cast Vulnerability Hex (VH) and Brand (B) on the Sky Horror and immediately cast Winter Blast (WB) and Dead Drop (DD) on it. If successfully brittled, the resulting combo will bring down half of the boss's health bar, if not brittled, it is at least guaranteed to bring down at least a third. Your top priority in the second phase is to eliminate the Sky Assassin before it can cloak and murder your party members, your second priority is to keep the enemy mobs from targeting Tallis and your mage who are key to bringing down the boss. Repeat the VH+B=>WB+DD every time the boss returns and it should go down pretty fast. It should be noted that if the Sky Horror takes so much damage that the AI confuses the battle phases and teleports it to the middle of the battlefield while on cooldown, this allows you to attack it with complete impunity.
Other than this, there are still a good dozen+ enemies to contend with, including no fewer than four Elites:
* The first wave of enemies mainly spawns to the right of the force field and the second wave mainly spawns to the left of the force field. Kill the Assassin, which is vulnerable to spirit damage along with most of the Cultists, as soon as it arrives. Positioning the party tank in those corners before they spawn will help to divert their attention from the rest of your party.
* The Sky Rogues (which are most of them, including Archers and the Assassin) are greatly vulnerable to spirit damage. 
* The Sky Warrior is functionally identical to a Shadow Warrior from Long Way Home and carries the same weaknesses, including spirit. If you picked up the Sacrificial Dagger, it is a purely spirit damage weapon, thus it deals double damage to the Sky Warrior and also influences talent damage. A dual-wielding rogue can use this to deal great damage to virtually every enemy, at the cost of being less effective against the Sky Horror, but a rogue Hawke or Sebastian can use The Houndmaster's Short Bow to compensate.
* The Sky Priests, however, have the same typing as Apostate Mages, thus they are immune to spirit on Nightmare and all other elements only deal their normal damage. Use Brittle combos to take care of them while Tallis silences them with Cover-Up.
* As always, take out the archers and mages before melee fighters, otherwise kiting doesn't do much good.
All things considered, the fight is completely avoidable if you want the quest completed in your journal. Simply don't take the book and you won't even have to fight them, you'll obtain everything of value from only taking the dagger and belt.
== Rewards ==
:300 XP (quest completion)
:850 XP for the fight (at Level 15)
:
:
:, from the Book of the Lady
== Gallery ==
HoDA_Sky_Horror.jpg|A Sky Horror in Heroes of Dragon Age
Promotional_Horror.jpg|Artwork of a Sky Horror in Heroes of Dragon Age
Category:Mark of the Assassin quests