I will tell you what happened in the duel. Leechner’s blood did something to Uriel once it got inside his system, changing him. He thirsted for more and did so. He overpowered Leechner into a hold that would be tough to get out of, bit into his neck/shoulder, and began to feast on his blood. He didn’t become a vampire if that’s what you’re thinking. Uriel’s blood became corrupted because of Leechner’s. When Ariema came down, she was witnessing the other members feasting on Leechner’s dried corpse to get the last bit of his blood with Uriel over watching them. That’s when she sacrificed herself. But somehow, Uriel and the 7th Regiment survived the destruction and disappeared. But now Uriel has resurfaced with one goal: to become a god. And the 7th Regiment is his army, except for one. Neveen, ranger of the regiment fled Uriel’s influence and grasp and took the rebuilt Vellan as her sanctuary. The cursed blood of Leechner that flows through her makes her have an unquenchable thirst for blood and one per new moon, she hunts for a human to drain. This is where Scar Night heavily influences this part of the campaign.