Based on no particular Bhaalspawn, but I like to think everyone's thought of something along these lines at least once.
Narrator: Hey there, Billy! Do you want to be CHARNAME, a Bhaalspawn of incredible power?
Billy: Do I ever! That sounds neato!
Narrator: Great! The first thing you need to know is that your daddy is Bhaal, God of Death and Murder!
Narrator: AND DADDY HATES YOU
Narrator: The sole purpose of your creation was to serve as a sacrifice to empower his resurrection.
Billy: Then what about my mummy?
Narrator: She also hates you, and if things had gone as Bhall originally planned, would have been the one sacrificing you.
Narrator: Not to worry, Billy! You get an awesome adoptive father, who guides and teaches you!
Narrator: And who is then killed by your brother. Who hates you.
Narrator: But don't worry Billy! There's plenty of perks to being CHARNAME, especially for a strapping young man such as yourself. Just look at all these lovely ladies you can romance in the second game! Introduce yourself to them, Billy!
Billy: Hi, I'm Billy.
Jaheira: MY HUSBAND IS DEAD
Jaheira: But CHARNAME is here... Yeeeeeeeeeeessss....
Billy: Uh... I'm not sure I'm comfortable right now.
Jaheira: Young, virile CHARNAME....
Billy: I-I need an adult.
Jaheira: I AM AN ADULT!
Narrator: Haha, that's about enough, you crazy cougar. Perhaps Jaheira isn't quite right for you, Billy. But what about Aerie?
Aerie: Hi there! I'm cute as a button!
Billy: Uh, I guess you are.
Aerie: Oh, you said it. You just admitted I'm cute.
Billy: I guess I did?
Aerie: Well, now I'm going to fawn over you and make you deal with all my crushing self-esteem problems for the next fifteen hours.
Aerie: SAY YOU LOVE ME OR I LEAVE THE PARTY
Narrator: Alright, so maybe Aerie isn't ideal for you either, Billy. Let's try Viconia.
Viconia: Here's a walkthrough for my romance. Read it.
Billy: But I wanted to play without a walkthrough...
Viconia: Then I'm almost certainly going to leave your party in a huff at some point. On an unrelated note, can you pass me Crom Faeyr?
Billy: Then... If I follow the walkthrough, you won't leave?
Viconia: Yeah, sure.
Billy: OK! I can work with this!
Narrator: That's great, Billy! You've found love!
Narrator: Now to make it really hard for you to enjoy that love, I'm going to install Ascension.
Narrator: Don't worry, you won't be affected by it for the next 150 hours at least.
*150 hours later*
Billy: WHAT IS THIS
Narrator: That's the stuff, Billy!
Billy: WHY ARE THERE DRAGONS EVERYWHERE
*190 hours later*
Billy: Well, I made it.
Narrator: Good job, Billy! You've claimed the Throne of Bhaal, and rejected its power to be with your love, Viconia! Don't you feel fulfilled?
Billy: You know, despite how horrifyingly difficult the whole journey was, I do!
Narrator: That's great! By the way, Viconia dies in her epilogue, leaving you to begin a crusade of vengeance.
Narrator: Good job, Billy!