The Deep Roads Expedition - p. 4 Dragon Age II Guide
Last update: 11 May 2016
Step 7: Fighting the Ancient Stone Wraith
Irrespectively of whether you decided to cooperate with the Stone Abomination or eliminated it, you should go through the door leading east #1. After reaching a big room, the Ancient Rock Wraith #2 will appear (M46, 5), serving as the main boss of this quest.
The fight will have a slightly different course than the ones you had until now. Performing normal attacks won't be enough, as in some situations you will have to act in a very specific way to keep your party alive.
As the fight begins, I'd suggest dedicating some time to learn the most common attacks of the boss. The Ancient Wraith will be able to teleport from one place to another #1. He can also deal considerable damage in direct combat #2 and in such situations you should look out for the lesser armoured party members, keeping them away from the boss and quickly healing if needed.
Attack the boss until he shrinks into a sphere and start to charge #1. You have to act QUICK if you want to avoid problems. Place your party behind one of the pillars located in the corners of the arena and wait through the attack #2. It's extremely important to block the other party members from moving during that time (H), as otherwise they might ignore your orders and exit the cover, which will probably result death on the spot.
Once the boss ends his charges attack, get out of the cover and start attacking him in a scattered formation #1. You however can't send all party members to do that, as around five Profanes will appear #2. It's best to send two characters to eliminate them. If you won't make it fast, the Profanes can cause considerable damage to your mages and rogues.
Keep attacking the Ancient Wraith until you see that it's trying to reassemble itself#1. I'd recommend retreating then, as the boss is likely to use a new attack, trying to pull your party members closer #2. If you won't make it, try to keep them away from the monster at all costs, as they can lose quite a lot of health.
Afterwards return to attacking the boss #1, while looking out for not only the already knows attacks, but also new ones. In one of them the Wraith will turn into a large rolling boulder #2 - also in this case the pillars will be useful, providing cover.
Keep attacking the boss until he starts charging again #1. Now you have to repeat the previous steps, that is hiding behind the pillar, waiting for the energy attack to end and head back, ordering part of the party to take care of the lesser Abominations #2.
In the further part of the battle, you will just need to repeat the actions described above and look after the health of your party members, as losing anyone will put you in a very uncomfortable position. Keep fighting until you drain the boss' whole health bar #1. You won't have to defeat the Abominations, as they will die together with the Ancient Wraith #2.