Vera Williams, though a First Tier card master, had very little actual combat experience, which made her combat power quite lacking. Her reactions were quick, and her mindset was sufficiently calm, but her two retaliatory "Fire Bullet Spell" Cards were easily dodged by the enemy.
Leonard Churchill was capable of killing, but he did not intend to waste the little Curse Power he had just accumulated on these two assassins.
After all, the essence of assassination is in its stealth.
Once discovered, getting entangled would be fatal for the assassin.
This was Machinery City, where not to mention the Rose Chamber of Commerce guards were numerous, Baron Bolton's private soldiers numbered over a thousand, who would quickly respond.
Even though these two fellows had the preposterous vampire bodies that enabled them to transform and were not easy to kill, they were still thieves.
Unable to kill quickly, if they were caught again, there would be no chance of anyone saving them alive.