Here we are, final boss, the capo di tutti capi (boss of all bosses), the big bad Archdemon. This fight takes place on top of Fort Drakon, and I have to say the Tolkien influence really shows here. Before you can even reach the fort, you have to fight through the main sections of Denerim through, I shit you not, at least 300 darkspawn including lieutenants and Generals. The Generals are no joke- I believe they are a mix of Champions, Reavers, and Blood Mages; they are pretty tough.
Depending on how you played through the game, you will have 4 groups of CPU controlled allies you can summon at will. I had humans, dwarves, elves, and magi to use. Without these troops, the final battle is pretty impossible to say the least, as there are waves and waves of darkspawn that come out at you as you battle the Archdemon.
The best strategy is to save your allies for the final fight. You may want to call in the dwarves when dealing with the darkspawn Generals, because the adds during the fight are a pain in the ass. You could just as easily though cast AOEs with Morrigan and be alright. The Darkspawn in this final encounter are different. The generic enemies have very little HP (names are white) and go down in one or two hits. There are a good amount of lieutenants here though (yellow names) who take a bit more of a beating. The Generals are full on bosses (Orange names) and there are two of them. They have a ton of HP and lots of status ailment type spells, hexes, and direct damage spells.
Since you cannot leave this area after you enter Denerim, be very careful when and where you choose to use poultices and balms. You won’t be able to get any more. There is one vendor just before the final area (why does this keep happening in RPGs?) who has a few balms and poultices, but not many. You will want to have a lot of spirit balms and greater or better poultices. I had 30 greaters and potents, and used 22 of them in the final battle.
My party is the same as it always is. The Archdemon is different than a regular dragon- it uses spirit based attacks and not flame. So equip your party with the very best gear you have, like large flawless spirit crystal for Shale (40% spirit resistance) and make sure they have a spirit balm active to up the resistances even more. You are going to need it.
When the battle starts, summon in Dwarves or Humans to start chipping away at the Archdemon. They aren’t going to do much, but the point to this is to keep the Archdemon and darkspawn distracted on them while you get to the nearest ballista. A ballista shot will do between 50-100 damage on the Archdemon, and you can get 3-5 shots from a ballista before it ‘breaks’. You can then run to the next one that is in range and use it, or, if you are a rogue, you can repair the broken ballista once or twice for another round of shots.
Once you reduce the Archdemon’s HP to 50%, the fight starts to get a lot harder. It will summon in waves of darkspawn against you. Make sure you get Morrigan or any caster out of harms way, and keep anyone healed who needs it. If they drop to 75%, heal them. Take your main and find the next nearest ballista to hit the Archdemon, at this point it is situated on a platform no one can reach except for ranged attacks like bows, ballistas or spells.
After the first few waves of darkspawn are dispatched, the Archdemon will fly back into the main arena and you can start melee’ing it again. It’s really a test of endurance- just keep your tanks healed, put hexes on it with your mage, and keep using ballistas to do significant damage. If you run out of allies, summon more. You will eventually pull through the fight and win. Sadly, you don’t get any loot from the Archdemon. You do get to see a cut scene and epilogue, and the chance to continue playing the game. I’ve already done all that you can do in the game (including killing Gaxkang the Unbound) so I guess I will have to wait for DLC.