For anyone who has already had a viral infection, for example: a staph infection, the flu, or maybe just a cold, you know that having these little viral machines running around in the your body and cause cell destruction can leave you bedridden for a week or, in severe cases, cause death. To the people living in the Americas, these conquistadors arriving in their homes were aliens bringing a plague (both in the sense of the comparison to the virus mentioned above, and in the literal sense of the diseases that Europeans brought with them). The other thing that made Columbus so dangerous was the technology the Europeans developed and used to immediately capture the attention of the natives. Most of which included the iron and steel tools that the Spanish brought with them; this included the thick plated weapons and armor that are most identifiable when looking for images of these conquistadors