An achievement guide for the would-be Demonheart hunter.
The ones you can obtain simply by following the story. Some are choice-dependent, but you should always get one or the other.
After the opening sequence, state you've chosen the adult demonspawn as your ally.
After the opening sequence, state you've chosen the younger demonspawn as your ally.
Sir Brash has joined the party.
Sabotage one of the Cult of Ravage's quest. You can do so by following Sinallion's advice and pay the thugs for the last task.
Don't pay the thugs, kill them and do as the priestess asks.
Rescue your demonspawn ally.
Board Sinallion's ship.
Infernal Traveler I
Travel to Raze's lair.
Free the trapped demonspawn in Raze's lair.
Infernal Traveler II
Travel to Thayn's lair.
Defy Thayn and side with humanity.
Side with Thayn and agree to become the Apocalypse's mother.
Tied to the romance options you choose. Starting a romance from the opening sequence allows you to kiss that character as soon as you see them, thus earning the related achievement immediately.
Kiss Sir Brash.
Sinallion is a new character, and cannot be selected right from the get-go. You get two chances to kiss him: the first in Bekka's inn if you choose to visit him after he's been wounded and hesitate to leave him like that, the second in the ship's cabin.
To earn this achievement, you need to be careful, because it can only trigger if Thayn visits you in the bed in Raze's lair. You must start the game selecting "no one" when you're asked who you're having an affair with and then proceed to avoid Ari, Brash and Raze's attempts to flirt with you. You can, however, kiss Sinallion, as he doesn't join you in bed, unlike the other love interests.
You select your alignment right in the beginning, so you can start from 80% of your chosen alignment (i.e. 80% Good 80% Tactful). The achievements can be easily earned if you act accordingly to your choices. On an estimate, each relevant dialogue option earns you around a 5% shift.
Reach 100% Good. Be nice, don't be eager to murder, spare whoever you can and criticize Brash and Ari's tendency to murder when you get the chance.
Reach 100% Evil. Look forward to all the murder and mayhem you can spread, don't hesitate to stab certain people, plot with Ari, Brash and Raze.
Don't Talk To Me
Reach 100% Defiant. Be rude, if you see a dialogue option containing a swear word, smash it. I recommend starting a new save solely to insult everyone and get this achievement, because otherwise you risk getting stabbed in the back by your very outraged companions during Thayn's confrontation.
Nice and Smiling
Reach 100% Tactful. Be polite. At least outwardly.
These achievements can be earned during the story, but they require you to take some extra steps.
Earn the Poison I skill. To do so, you need 100 Poison Powders.
Earn the Poison II skill, at the cost of 150 Poison Powders.
Earn the Poison III skill, at the cost of 200 Poison Powders.
Sell 30 Healing Salves. You need a total of 300 Healing Powders to do so, but you can also find some salves by looting corpses or barrels. Any merchant is fine.
Please note that, to craft powders, you need to consistently look for ingredients to use. Flowers, mushrooms and animal/monster parts all qualify: for example, a Big Spider Leg can be ground into 2 Poison Powders, just like the Glowing Mushroom, while Deer Antlers and Poppies can be transformed into Healing Powders. Flowers and mushrooms have a high chance of respawning when you visit the area again. An especially good spot to farm Poison Powder ingredients is the unded-infested area in Ravage. The undead respawn frequently every time you visit it, and they have a chance to drop from 1 to 2 Undead Eye, which can be used to get 2 Poison Powders each.
Sell a human skull. Skulls are usually looted from drawers, armoires and Crawlers (the slugs you find in Inferno). You should come across one of the first skulls in Raze's lair.
Find Mr. Edgardo. He's in Raze's lair. Interact with him to get the achievement.