You face them twice, both times on typhon. First time you accidentally-on-purpose kill the farseer who is stopping the exterminatus fleet from arriving and the second time when you return and sacrifice their exarch to get the Avatar.
i played DoW2R campaign about one year ago and if i remember correctly Alaitoc forces try to talk first with the Biel-Tan forces because they didn't new the Biel-Tan's intentions, which was also the same goal of Alaitoc(do note that Alaitoc's true goal was to save the farseer Taldeer's soul stone which they didn't find out till they end up in the space hulk) to save a crashed craftworld probably of Alaitoc , but before any diplomacy Biel-Tan forces strike at the Alaitoc and some **** gose down and in the end Alaitoc kills the Biel-Tan farseer which was keeping the exterminatus fleet at warp from entering the real space.The second fight with Biel-Tan in the destroyed typhon primaris was for the Avatar of Khain. Alaitoc win this by destroying the webway portal which Biel-Tan used to retreat.
I love the Blood Ravens... mostly because I think pre-heresy Thousand Sons were awesome and I like the idea of a loyalist Thousand Sons chapter.
Blood ravens are where they should be, not in this game. I just don't wanna play DoW when playing EC. There are good things in their background and possible history, but they have nothing to do here.
Bah. Heresy this heresy that. If I acquire something that allows me to destroy the traitors more effectively then I might as well keep it.
Considering the Bloor Ravens have ''liberated'' more loot from their fellow space marine chapters,,, some of those items being quite litteraly the most holy relics of said chapters, they make the entire orkish race's looting look like petty theft!
Blood Ravens are an official GW army now, not limited to the dawn of war series, and are mentioned in the lore beyond the dawn of war series, so this "They aren't canon" or "they only exist in the DoW games" thing needs to stop. Remember the official GW t ract: Everything and nothing is canon. In reality this being the Thirteenth Black Crusade or there abouts means the Blood Ravens are currently in the midst of a chapter civil war in Aurelia, or shortly thereafter, and therefore in no position to help anyone.