For the Dawnguard, you have to deal with the vampires. For the vampires, you don't deal with the Dawnguard. Why isn't there a quest for the vampires to eradicate the Dawnguard? Isran is invincible and therefore cannot be killed, yet Harkon can be slain if you are Dawnguard? Seriously Bethesda, what is up with this?

There is its a radiant quest for the vampire side.

Do any of these quests involve the death of Isran?

Radiant quests..

You get super buffing artifacts for your character in normal and Vampire lord form..chalice of the ancients upgrades and blood potions...and you can turn your wife into a Vampire....and settle things with the dawnguard.

Save after doing each radiant quest though,..rumors of it bugging out at times.

Well the quest is to kill the dawnguard leaders at their headquarters.

*Adolf Isran

Yes, I believe so, have not yet finished the Volkihar side.

The story ending svcks lol I finished Harkon, and Isran basically says good job and walks away.

So basically once you end the threat nobody really cares. Unless I missed something?

I figured the lowlife vamps would be able to kill Isran...?

You can. Although it was less of a "be careful, they're tough" scenario and more of a "Hey, these guys are getting annoying. Could you wreck them Molag-Bal style? Thanks, you're the best." type of deal.

That shouldn't have been a side quest.

Welcome to Skyrim mate! The land you save numerous times, only to find out no one gives a crap!

OT: It was never " Volkihar vs Dawnguard" It was "Dawnguard vs Volkihar". The Vampires didn't care until later on, really. They had other things to worry about than some 3rd rate Vampire Hunter guild. Once those things were dealt with they had nothing keeping them from putting an end to the Dawnguards pathetic attempts at wiping them out. And face it, if the Player ignored both Sides Dawnguard would've been rofl stomped by Harkon and his followers, with or without the Eclipse.