Surion is not so willing to part with such secrets. He only assures the rest of us that he has every intention of cooperating against the larger threat.

[She does not seem happy about this, but she is ever-patient.]

You could try befriending a blacksworn, I suppose, if you felt like taking the risk. But it is risky. Uniting against a common threat does not erase what Deathwing has done.