Speak with Cazul in the Cleft of Shadow.
The time has come for you to learn more of the summoning magics. You will learn to summon a succubus, a creature of incredible mental powers. It can lull those of weak minds into its servitude--but have no fear! I feel certain that you will be equal to the challenge.
A succubus can only be summoned when baited with an item that represents great devotion and love. I leave it to you to find such an object.
A suggestion? Speak with Cazul... There seems to be little the ancient warlock does not know.
Hm... Zarm. You are still new to your path, but I sense the possibility for greatness in you.
You were born with gifts, <name>. See that they do not go to waste.