So, Throne of Bhaal.
Do you remember the scene when Gorion and Alianna tell you about your origin? When a demon takes Gorion's face and tries to separate you from your love interest by summoning ghosts?
Those are both powerful scenes. Cool ones, seriously. And they got me thinking: all right, we got this great conflict and some terrible deeds, like a mother trying to sacrifice her baby, but what about the people behind the story?
What about your foster father, who sacrificed himself to save you? Will you really never get a chance to talk to him again, only through Solar's scenes? What would he say if he saw you at the end of the Throne of Bhaal? What would he advise?
What about your mother? Will she remain a cardboad figure? Was she Gorion's friend once, like he wrote? Was she a victim? What was her life like before Bhaal?
And seriously, did she ever love you? Did she ever love anyone?
So, that's how Reunion was born.
Go to Amkethran, enter Chapter 9, and take Nalia into your party. You can drop her later, but she's got LOTS of dialogue in the mod, so I wouldn't. Basically, she's the Imoen of Reunion: talks, interjections and commentary on everything. But Imoen and Sarevok have things to say, too, during your conversations - not as many, though.
And, like I promised: learn your mother's true story, look into Gorion's eyes, and ask the questions you've always wanted answered.
(also, you may meet another sibling. Shocking, right?)