Is Sanguine supposed to show up and help you?

I was doing the first quest in "Arniel's Endeavor" where you have to get the staff from the conjurers, and in the boss part of the fight, I see someone already fighting him, it's Sanguine. I grabbed a screenshot here after everything was done:

http://imgur.com/Oew2c

when you try to talk to him, he has some random lines, usually from the drunks in towns (e.g. "I don't owe you money, do I?").