Baldur's Gate: EE - Achievement Guide. Excl Siege of Dragonspear

Finished, After completing the game on Legacy of Bhaal difficulty several times over the years the achievement has final unlocked. Updated BG:EE V2.5.
I don't know why it took me so long to work this out but if you are having difficulty with any of the achievements you can import your high level characters from BG2:EE

You will unlock these just by playing through the game

Leave Candlekeep, the only home you've ever known.
Complete the Prologue Speak to Khalid and Jaheira at the Friendly Arm Inn.
Self explanatory.
Killed Mulahey and ended the threat to the Nashkel mines.
Complete Chapter 2
Ended the bandit threat to the Sword Coast.
Complete Chapter 3
Killed Davaeorn and shut down his mining operation.
Complete Chapter 4 Seems buggy took me a couple of attempts to get
Reported Rieltar's activities to Duke Eltan in Baldur's Gate
Complete Chapter 5
Made your way through the catacombs beneath Candlekeep.
Complete Chapter 6
Killed Sarevok and ended his threat to Baldur's Gate and the Sword Coast.

You will get these by completing specific quests some are mutually exclusive. So save before deciding which you want to get. I will try to list them in the order you can gain them.

Complete the following quests during the prologue:

• Dreppin's Cow
  
• Phyldia's Book
  
• Reever's Storehouse
  
• Hull's Sword
  
• An Errand For Fuller
  
• Firebead's Scroll

Defeat Carbos and Shank.
Carbos and Shank are the two assassins who try to kill you during the Prologue. They can be found in the Bunkhouse and Priest's Quarters.
Teach Marl a lesson. / Convince Marl to back down without resorting to violence.
When you enter Feldepost's Inn in Beregost a man named Marl will speak to you.
Threaten him and kill him to gain "He Started it".
Use the following conversation options; 1, 1, 3, 3, 1 to gain "Use Your Words".
Bring Firebead a copy of "The Fateful Coin."
Firebead's home is accross from Feldpost's Inn and you can buy a copy of "The Fateful Coin" from Feldpost's Inn.
Side with Silkie against the mercenaries in Beregost. / Side with the mercenaries against Silke in Beregost.
Speak to Garrick outside the Burning Wizard Inn in Beregost. Agree to help him and he will take you to Silke. Speak to her and the mercenaries will turn up. Kill them or Kill Silke
Return the stone maiden at the Nashkel carnival to life.
You will need a Stone to Flesh spell. Go to Nashkel carnival outside the armour tent there is a stone lady use the spell on her.
Send the witch Dynaheir to the afterlife. / Set the witch Dynaheir free from her prison.
Dynaheir is found in the east pit in the Gnoll Stonghold. You will need to speak to Edwin in Nashkel to gain Witch Slayer by completing his quest to kill Dynaheir. To gain Witch Savior just release her fom the Gnoll Stronghold.
Protect Prism until he completes his masterpiece.
Prism can be found by a large rock on the Nashkel mines map south of the mine. Speak to him and tell him you will protect him. Once done collect the emeralds for the next achievement.
Return the stolen emeralds to Oublek.
Take the emeralds from Prism and return them to Oublek in Nashkel.
Return Drienne's cat.
Drienne can be found by the waterfall in the area SW of Nashkel or East of Gnoll Stronghold.
The cat can be be found at the bottom of the waterfall.
You will need CHR 10 to get this achievement - thanks to FhqwhGOD
Appease the ghost in the Ulcaster ruins.
At night near near the ruins in Ulcaster you will find a ghost. Speak to him several times and he will give you a quest completed it and you will gain the achievement.
Return Joseph's greenstone ring to his wife.
The ring can be found at on the third floor of Nashkel Mine at the start. Return the ring to Joseph's wife in Nashkel.
Save Hulrik's cow.
Hulrick and his cow can be found in the area north of Nashkel Carnival. - Bugged save before entering the area.
Discover who let the kobolds into Gullykin.
Enter Jenkals House in Gullykin go down the stairs and Jenkal will question what you are doing here reply with option 3. Thanks to FhqwhGOD for pointing this out
Assist Gallor at the archaeological dig. / Assist Charlston Nib at the archaeological dig. / Find and keep an artifact at the archaeological dig.
In the Archaeological Site an area West of Nashkel and North of the Gnoll Stronghold. Speak to Charlston Nib and convince him you arn't there to rob him. After Gallor will approach and talk to you, agree to kill Charlston.
Enter the tomb and after the cut scence defend yourself and open the sarcophagus, take the idol. You should get "This Belongs in a Museum". Next Kill Charlston for "Assist Gallor". Leave the tomb and kill the creature for "Faerunian Idol". I Would however save before becasue killing Charlston will result in a large reputation drop.
Put an end to Captain Brage's mad rampage. / Convince Captain Brage to return to the temple of Helm.
Captain Barge can be found SE of the Tomb mentioned previously with a lady called Laryssa. She will approach you and ask for help. you can choose to help or kill Captain Barge. If you choose to help the answer is DEATH.
Side with Seniyad in the Cloakwood forest. / Side with Aldest Sashenstar in the Cloakwood forest.
Speak to Aldeth outside his cabin in Cloakwood. The cabin is located in the middle of the first Cloakwood area. Agree to his request and Seniyad will show up.
You will need CHR 10 again for this quest to show up.

Side with the fishermen near Baldur's Gate. / Return Tanya's stolen property.
This quest starts by speaking to Sonner in the area North of Friendly Arm Inn. He will mention a witch affecting fishing. Go to the bridge in to Baldur's Gate and keep walking along the coast to speak to Tenya, the "Evil" Witch, and she will attack. Try not to kill her and you will get another quest to aid her.
Depending on your choice you get the corresponding achievement.
Restore Camah to life.
The person you are looking for is actually called Tamah. You will need another Flesh to Stone spell. You can find Tamah in the area North of Gullykin in the NW of the map in a small clearing. Be careful as there are Basilisks in the area. Don't ask for a reward or you will get a reputation penalty.
Steal a telescope from the Hall of Wonders.
Speak to Brevlik in the Elfsong Tavern, East Baldur's Gate and he will give you the quest to steal the telescope. The Hall of Wonders can be found in West Baldur's Gate.
Bring Casson's body to Tremain.
North of the Hall of Wonders is a guy called Varci he will ask for your help, agree and follow him to the house. Here speak to Tremain and he will give you the quest to retrive Casson's body.
Help Abela the nymph escape.
In North Baldur's Gate behind the Palace a man named Ramazith will approach you and ask for your help. Agree and he will give you a quest to get a Nymph from a Mage named Ragefast. Ragefast can be found in his house behind the Hall of Wonders. Kill Ragefast and release the Nymph for the achievement.
Sent Tamoko to the afterlife. / Convinced Tamoko to aid you.
When you return to Baldur's Gate after escaping head to Sorcerous Sundries. Outside you will find Tamoko, the Cleric who attacked you with Sarevok. Be nice and agree to meet her by the Flaming Fist HQ. This can be tricky with the Flaming Fist hunting you.
When speaking to her outside the Flaming FIst HQ agree to her request and kill Cythandria.
Your final encounter with Tamoko is outside the Temple of Bhaal in the Undercity. use the following conversation options 1, 3, 2. Depending on your CHR will depend on how well it goes she will either attack you or walk away. I had CHR 16 and it took a couple of reloads to get it to work.
Explore Durlag's Tower and defeat the evil growing within it.
Before going to Durlag's Tower Go to Ulgoth's Beard and enter the Inn speak to Hurgan Stoneblade and he will give you a quest to get the Soultaker Dagger. After it is pretty straight forwarded make your way through Durlags Tower and Labyrinth and defeat the Demonknight at the end for the achievement. Don't forget to take the Soultaker Dagger from It's body for the next achievement.
Destroyed the demon Aec'Letec.
Return to Ulgoth's Beard with the Soultaker Dagger and you will be robbed of it when you enter the area. Speak to Hurgan again in the Inn and tell him what happend. He will ask you to retrive the dagger from the cult in the storehouse. Head in to the storehouse kill the cult members and the demon Aec'Letec for the achievement.
Have Neera, Dorn, and Rasaad in the party at the same time.
Neera can be found in Beregost, slightly South East from where you enter. Defend her from the wizards and let here join your party.
Dorn is first met in the friendly arm in where he mistakes you for a server. After speaking to him you will get a Journal entry "How Rude". You will meeting him again when you try to travel to Nashkel Mines. You will be waylaid by bandits and Dorn will come along and aid you. After the fight you can get him to join.
Rasaad is outside the Nashkel Inn surrounded by commoners. Speak to him and he to get him to join you.
Find Baeloth the Entertainer and convince him to join your party.
Baeloth can be found in South Larswood by the broken tower. You will need to be level 5 or higher for him to appear. just use option 1 for the conversation.
When I first tried to get this I did "All the Options" first and when I recruited Baeloth the Achievement didn't unlock

The rest, these have no quest related to them and most are pretty self explanatory. I will try to explain the easiest way to gain them. Most of the potions and spells can be bought from Sorcerous Sundries Or Black Lilly in the Thieves Guild(Ch. 7).
Note all these need to be done with your starting charcter. If you are still having difficulty with some of these and you have BG2:EE you can import your high level charater(s) from it.

Increase an attribute score to 25.
There are lots of ways to get a stat up to 25 the easiest will probable be drinking Potions of Mind focus as they stack and will get you +3 Int and + 3 Dex per potion.
Can no longer be gained by starting a new game in story mode.
Speak to all the Candlekeep tutors and learn what they have to teach you.
There are 14 tutors now in Candlekeep, 2 in the Inn 11 in the outer wall and 1 in the inner wall with Keep, he is by the entrance near where you start. - Thanks to shade169 for pointing out the "new" one.
Have an Armor Class of -15 or lower.
A high Dexterity(16+) with good armour and accessories should work try a potion of defense. Potion of defense can be bought from Sorcerous Sundries in East Balder's Gate. What I used in Black Pit again a Fighter with base DEX 18 (-4 AC).
NB. Use a Potion of Agility to gain a base Dex 18 if it is under 18, alternatively;

• Take a potion Mind Focusing - DEX +3 (-1/-2 AC) You can drink multiple of these and it stacks up to DEX 25
  
• Take a potion of Defense (Base AC 0)
  
• The Dusty Rose Ioun Stone Helm (-1 AC)
  
• Pellans Shield +2 (-3 AC)
  
• The Guards ring +2 (-2 AC) or Improved Cloak of Protection +2 (-2 AC)
  
• Boots of Phasing (-2 AC)
  
• Caste the level 4 Priest spell Defensive Harmony (-2 AC)

Have a Lore skill of 100 or more
I believe the only way to get a lore over 100 is with a high level Bard. If you are close try a potion of Wisdom if you have less than Wis 18
Become a Grand Master.
The only way to do this is have 5 pips in a weapon skill as a Level 9 Fighter.
I had to do this in Black Pit as the XP Cap in the original game is still lvl 8?
Complete the game solo.
Complete the game on Legacy of Bhaal difficulty.
Finally unlocked 16/03/19
A helpful guide by traedog93 for anyone struggling that doesn't want to cheat.
Complete the game on Story Mode difficulty.
Start and Complete a game in "Story Mode"
Finish the game without any party members dying.
This appears to only apply to the party members dying whilst fighting Sarevok
Finish the game with a full party of dead allies.
Reach 150 Hit Points.
A Fighter with high Constitution(17+) might work with a Monk.
Again had to do this in Black Pit I had a Lvl 10 Fighter with;

• The Pale Green Ioun Stone Helm (+10% HP)
  
• A Potion of Fortitude (18 CON)
  
• A Potion of Heroism (+10% HP)

The Potion of Heroism stacks so if you have enough you should be able to boost it all the way to 150. There is also a Potion of Power (+20% HP) you can buy it from Black Lilly in the thieves Guild. There is one on the mage in the ruins under Jenkals house.
Acquire Heroic reputation.
Reputation starts between 8-12 depending on alignment and you need to get 18. Most of the main quests and a number of sub quests will increase your reputation.
Acquire Despised reputation.
Can be gained with Oathbreaker below. In the prologue kill the two nobles upstairs in the Inn. Would not recommend doing this with a character you will be using.
Kill 1,000 creatures.
Needs to be done in one playthrough. What I did was go to Gnoll Stronghold before fighting Sarevok keep resting and you can spawn small groups of Xvarts and Gnolls.
Become a Fallen Paladin or a Fallen Ranger.
As a Paladin or Ranger murder someone. see above, Villian on how to get this the easy way. Would not recommend doing this with a character you will be using.
Have Bless, Chant, and Luck active at the same time.
Cast the Lvl1 Cleric spell Bless, Lvl 2 Cleric spell Chant and the lvl 3 Wizard Spell Luck on your charcter. Bless and Chant are AOE so it it is only the Luck spell that needs to be cast on you.
Have Disease, Fatigue, and Poison active at the same time.
Best to start with fatigue then disease and finally poison.- as mentioned by Gugulug5000 you can use the lvl 4 Wizard Spell Contagion and the lvl 4 Cleric spell Poison after your character is fatigued. Save between each spell.

Main changes:

Enemies have more HP
Enemies hit more often making armour almost pointless without magic
Enemies are harder to hit
Damage and Crowd Control Spells are less effective

Party advice:

Use high level characters
Use ranged weapons and kite
Your summons have more health too so use summon wands and spells
True sight is a must so a high level thief is required in the party

Fights will take a while you just have to be patient.