As the Slayer, the player experiences a number of potent benefits.
Strength and Dexterity are increased to 25.
Constitution is increased by +5. This is affected by Constitution modifiers, such as the Claw of Kazgaroth.
The Slayer possesses dual claw attacks that strike as +5 Slashing weapons and inflict bonus Cold damage.
Bonus to Attack speed and THAC0.
Unless the Ascension mod is installed, maximum hitpoints are set to 100(more likely due to a bug for the 100 hp is intended as a bonus).
The Slayer is immune to Imprisonment, Charm, Confusion, and Illithid Mind Blasts.
Activating the Slayer Form is not without drawbacks. Firstly, 2 points of Reputation are lost each time the transformation is used. Secondly, the player's soul cannot withstand the Slayer's influence; after a certain time spent in Slayer Form, the player will begin to lose hitpoints. Even if they heal this damage, after a certain point, they will automatically die if they do not change back beforehand. The game prompts the player to change back by warning that they can feel themselves losing control.
The Slayer Form is acquired automatically by all versions of Gorion's Ward in chapter 4 of the Shadows of Amn storyline. Players starting the Throne of Bhaal storyline without an imported character receive this ability by default.
After the player has entered Spellhold, Irenicus traps them and strips them of their soul, costing them the Bhaalspawn abilities they previously had, but giving the Essence of Bhaal within them a chance to grow stronger. As they are leaving the maze of testing, an attack by Bodhi triggers a transformation in which Gorion's Ward becomes the Slayer and attacks Bodhi - and then turns on the party. They will revert to normal after a minute or two.
The first time the player sleeps after their first transformation, they will wake spontaneously and transform again, attacking the party before reverting to normal again.
Sleeping after this will cause the player to experience a dream. When they awaken, they will possess the ability to transform to and from the Slayer at will.
Because of its low hitpoint cap, the Slayer Form is often considered inferior to a high-levelled Warrior classed Gorion's Ward.
The Ascension mod, by Throne of Bhaal's design director David Gaider, includes an option to improve the Slayer Form, causing it to grow more powerful as the player increases their XP total and to eventually let the player transform into the Ravager as well as the Slayer. The most basic improvement is that the Slayer's hitpoints increase with the player's level.