Final answer:
A pandemic infectious disease like the Black Death can cause widespread destruction and present a strong conflict that must be overcome.
Step-by-step explanation:
An illness that can cause a widespread destruction and present a strong conflict that must be overcome is a **pandemic infectious disease**. A pandemic is an epidemic that spreads across multiple populations or continents, or even worldwide. One example of a devastating pandemic is the **Black Death (bubonic plague)** that spread throughout Europe.