Deep within the adamantium-lined walls of the high-tech prison known as the Vault, the world's most dangerous super-villains are kept in line by the stalwart Guardsmen. Each Guardsman wears incredibly advanced battle armor designed by Tony Stark and is skilled in a myriad of combat techniques. But a Guardsman's most valuable asset is his detailed knowledge of each super-villain's power - knowledge that comes in handy when dealing with the likes of Venom, Carnage, or any number of sinister symbiotes!