Dragon Age: Origins

Here's how you can get "Harrowmont's Ally" and "Bhelen's Ally" in one playthrough.

Note: I'm paranoid about closing storylines off too early, so I usually delay picking a side until the very last minute. So there might be a quicker way to do this, but this method definitely gives you a decision point where you'll only have to replay about two minutes of story in order to get both achievements.

First of all, the setup: I basically played both sides as far as gaining their trust. I accepted the initial tasks from both houses, got both of Harrowmont's champions to fight again, and turned both of Harrowmont's allies into enemies for Bhelen. At that point Harrowmont's emissary got mad but I agreed to play double agent for him, and cleaned out dust town.

Now you should be in a position where you're still begrudgingly trusted by both factions, and they'll both try to get you to go find Branka in order to get her endorsement. You'll also be finding out that Bhelen's pretty much a tool, but that's beside the point.

Play through the entire Anvil of the Void storyline. Whether or not you choose Caradin or Branka, you'll be given the opportunity to have a crown made so that you can basically choose the next king. After you get the crown, SAVE the game. This is your decision point. Leaving the anvil room you'll be given the choice to fast travel directly to the council chamber, where a cutscene immediately plays.

For "Harrowmont's Ally" declare that Branka or Caradin chose Harrowmont to be the next king. He'll thank you, Bhelen will reveal himself as a true douche, and you'll pretty much wipe the floor with him. After Harrowmont thanks you and gives you his pledge of aid, the achievement will unlock.

If you haven't gotten "Bhelen's Ally" at this point, just reload from your save and follow the instructions in that achievement guide.

Both "Harrowmont's Ally" and "Bhelen's Ally" are available in one play through with a careful save.

Leading up to your deep roads trek it doesnt matter who you run your errands for. You can complete Harrowmonts tasks or Bhelens, or even both (with careful dialog choices Im guessing). Just play however you see fit, head through the deep roads until you preserve or destroy the Anvil of the Void. SAVE HERE after youve received the paragon crown but before ou head back to Orzammars Council Chamber. When you do head to the Council Chamber a cut scene happens. Through a series of dialog options you can pick Harrowmont or Belen, even if you didnt help support them before you left for the deep roads.

Crown your King and reload your save. Do it all over again for the other achievement!

Once you return to the Orzammar Chamber of Assembly after the Anvil of the Void quest, you'll have to choose a new king for Orzammar. For this achievement, say that Branka or Caridin chose Harrowmont to be king. After a cutscene, Bhelen will go postal and you'll have to fight him and his guards. The fight is pretty straightforward. At the end of the fight, after a conversation with Harrowmont, you'll unlock this achievement.