original_query: What is the role of Viper and Alley Viper in the text?
query: What is the role of Viper and Alley Viper in the 'Invasion of Benzheen' storyline?
answer: In the 'Invasion of Benzheen' storyline, a Range-Viper and Alley Viper, along with other Cobra forces, use a civilian to trick Sneak-Peek into a crossfire, badly injuring him.  All the Vipers are later killed.