Bhaal's Domain is the ruined remnants of the former divine home of Bhaal upon the Lower Planes. Gorion's Ward and their party are dragged to this otherworldly desolation by the metaphysical link between the souls of Gorion's Ward and Jon Irenicus, after the latter's death amidst the branches of the Tree of Life in Suldanessellar.
This area is where the climatic events of Chapter Seven of Baldur's Gate II: Shadows of Amn take place. It is implied that it becomes the Pocket Plane in Baldur's Gate II: Throne of Bhaal.
Area Description
Irenicus lies hidden behind the Abyssal Door in the northern section of the map. To open it, Gorion's Ward must undertake the five Trials and retrieve the Tear of Bhaal hidden at the end of each Trial.
To the east is the Test of Pride.
To the west is the Test of Wrath.
To the south is the Test of Selfishness.
To the southeast is the Test of Fear.
To the southwest is the Test of Greed.
The Trials can be undertaken in any order. The first "examiner" will explain the Domain's nature to Gorion's Ward when confronted, and the final Trial will fully clarify what is happening and why the tests are occuring.
Once a Tear of Bhaal has been acquired, clicking on the Abyssal Door will remove that Tear from the party's inventory, progresses the party a step towards the FInal Battle, and imbues Gorion's Ward with a special ability, dependent on the Trial that the Tear comes from and the choice that they made for solving that Trial.
Choosing an Evil path may potentially cause Gorion's Ward to experience a change in their Moral alignment to Evil.
Test of Pride
Upon entering the Test of Pride, a demon begins to flatter Gorion's Ward about their might, explaining that a powerful beast lies just beyond and exhorting them to defeat it so they may claim the Tear. If the player remains suspicious of its flattery, however, the demon is eventually forced to confess that the guardian may just give them the Tear if they ask it nicely.
If the player declares they will ask for the Tear, then demon comments on how humility, properly used, can be a source of great power. It vanishes and the Tear's guardian, a Black Dragon, hands it over peacefully. This is the Path of Good. The Tear of Bhaal will grant Gorion's Ward +20% Resistance to Fire, Cold and Electricity.
If the player arrogantly or reluctantly declares they will fight the guardian for the tear, then the demon vanishes, forcing them to confront a Black Dragon. When slain, it grants the party 22000 EXP, as well as leaving behind loot in the form of the Tear of Bhaal, Scrolls of Time Stop, Wail of the Banshee and Sphere of Chaos, 20 Bolts of Lightning, 20 Arrows of Dispelling, a Ring of Protection +2, and a Robe of the Evil Archmagi. This is the Path of Evil. The Tear of Bhaal will grant Gorion's Ward (possibly the party) 200000 EXP.
Test of Fear
Upon entering the Test of Pride, a demon explains how the Tear of Bhaal can be reached by either of two routes; a chamber filled with Beholders (specifically, Elder Orbs and Gauths) or a chamber where potent magic will attack the player's mind. They offer the player a Cloak of Bravery, fashioned from the skins of nymphs, to defend them against the terrors beyond.
If the player refuses, they must still make their way through either room. Any effect that grants Fear Immunity, such as Mazzy's Invoke Courage special ability, will protect them against the madness room. The beholder room is simply a tough fight.
If the player accepts the Cloak of Bravery, then the Tear of Bhaal will grant Gorion's Ward a +2 bonus to Constitution. This is the Evil path.
If the player refuses the cloak, then the Tear of Bhaal renders Gorion's Ward immune to any weapon that is not equivalent to a +2 or higher enchantment. This is the Good path.
Note: Refusing the Cloak of Bravery, but going through the madness path first, might lead to the alignment of Gorion's Ward changing even though they receive the Good Path Tear's reward.
Test of Selfishness
Upon entering the Test of Pride, a demon explains that Gorion's Ward must take one of two paths; the one on the left will drain away some of their power, whilst the other will steal the life from one of their companions. The demon then kidnaps and paralyses a random party member, leaving the player to make their choice.
Taking the Good Path in this Trial will cost the player: -2 from Maximum Hit Point Value, -1 Dexterity, and - an undetermined amount of EXP. The Tear of Bhaal will grant Gorion's Ward +10% Magic Resistance.
Taking the Evil Path will kill the abducted companion, though they can be subjected to a Raise Dead or Resurrection spell without issue. The Tear of Bhaal will grant Gorion's Ward a +2 bonus to their Armor Class.
Test of Greed
Upon entering the Test of Pride, a demon tells Gorion's Ward that the Tear lies in the possession of a powerful guardian, and gives them Blackrazor, a Longsword +3, to combat it with.
At the end of the pathway, the guardian is revealed as an imprisoned Genie, who gives the player a riddle, which they puzzle out means that they can either use Blackrazor to slay him, or they can set him free by simply giving him the sword.
The Good path here costs the party Blackrazor, but rewards them with 20000 EXP.The Tear of Bhaal will grant Gorion's Ward +2 to all Saving Throws.
The Evil path here means the party must fight the Enslaved Genie. A Spell Trigger launches an Improved Mantle, Mirror Image, Protection from Fire, Fire Shield (Red) and Globe of Invulnerability upon the beginning of the battle. The death of the Genie rewards the party with 11000 EXP and allows them to keep Blackrazor. The Tear of Bhaal will grant Gorion's Ward +15 Max Hit Points.
Test of Wrath
Upon entering the Test of Pride, the party finds themselves confronted by Sarevok's Wraith, who brashly attempts to coax them to surrender to their rage and adopt the form of the Slayer.
If the player rises to Sarevok's taunts, or uses the Slayer Form special ability, then they count as taking the Evil path. The Tear of Bhaal will grant Gorion's Ward a +2 bonus to Strength.
If the player does not rise to Sarevok's taunts and does not activate Slayer Form, then they count as taking the Good path. When they return to the Abyssal Door, The Tear of Bhaal will grant Gorion's Ward a +1 bonus to Wisdom and a +1 bonus to Charisma.
Wraith Sarevok is worth 20000 EXP.
Final Battle
After all five Tears of Bhaal have been used, Irenicus storms into the Domain. Some banter is exchanged and he transforms into the Slayer, as well as summoning two Pit Fiends and two Glabrezus to aid him.
Warning: the Pit Fiends and Glabrezus break the normal rules and are capable of attacking the party even if they have Protection from Evil applied.
Irenicus as the Slayer will engage in minor spellcasting for most of the battle; teleporting across the field and using defensive spells like Mislead and Fire Shield (Red). After his health has been reduced low enough, he will start attacking physically and using more offensive spells. Killing him is difficult, as his health regenerates very quickly, but not impossible.
When defeated, the ending cutscene is triggered.