If you were going to manufacture stats for your character. What rules would you apply? Being a bhaalspawn they deserve high level stats. How about: +1 to all stats, that way you can save the tomes for an NPC.
+2 points in charisma at start. Or just +2 in a stat of your choosing.
+2 points in charisma at start. Or just +2 in a stat of your choosing.