I have the Divinity II - Ego Dragonis OST (free from the composer's website http://www.kirillpokrovsky.com/)
The Flames of Vengeance OST is not on the website and is not included in the Developers cut soundtrack.

Does anyone have the complete soundtrack or a link for Flames of Vengeance?

There is a gamerip located here (Thread 71649), link still up. OGG Vorbis files