This vampire was not a Marquis, but he could unleash the Source Blood Offering. That could only mean that this black-robed man's parents were pureblood vampires.
The Source Blood Offering was a forbidden technique among the Blood Kindred. It was second only to Twilight. Once it was unleashed, it was irreversible. The black-robed man was a Blood Kindred Grand Earl. He was comparable to a Martial Arts Grandmaster third realm existence. Even if he did not unleash the Source Blood Offering, Mo Wen did not want to battle with him.
The Martial Arts Grandmaster third realm was the pinnacle of the realm. Even though Mo Wen's current cultivation had broken through to the pinnacle of the Golden Elixir Realm, he was still no match for a Martial Arts Grandmaster third realm strong practitioner. Maybe he was more powerful in some areas compared to a person of the Martial Arts Grandmaster third realm, but his overall ability was still far weaker.