No. The Lord of Chaos is trying to get back into Rivellon to rule, not destroy all of creation.
AFAIK there is no connection between the baby and Ulthring. Like the sword, the baby was infused with an aspect of the Lord of Chaos, though.
I was referring to in-game books. The only RL book is the Child of Chaos novella (included as a pdf with Divinity 2 Developer's Cut, and in the extras for the GOG version of Beyond Divinity).
