Morrigan's Ritual

After speaking with Riordan and learning how the Arch Demon can be killed Morrigan may be waiting in your room as you return to rest before The Final Battle. You may need to be a male and in a relationship with her for this to happen, that's how it happened for me. If Morrigan is there she will offer you an alternative to Riordan's plan. She claims to know a blood ritual that will allow the Warden's to free themselves of their burden. All you have to do is bed her that night and she will concieve a child. The child will consume the essence of the Arch Demon at the moment of it's death and she says after that she will leave you and raise the child on her own as she see's fit. If you refuse her she says she will leave right then and you will not have her for the final battle. Also if you refuse she will attempt to get you to convince Alistair to help her concieve the child; you can then decide to do it yourself, help her convince Alistair, or refuse again at which point she does leave you.