What is general Zarroffs main reason for hunting humans

He tells Rainsford that he had come to the point in his life that he felt bored with every other type of animal because "they were no match at all for a hunter with his wits about him and a high-powered rifle." Basically, there was no more intrigue or excitement in hunting for Zaroff, so he decided to hunt man.

  plan: i will begin with a quotation about the importance of unity in a community. then, i will state my claim that an activity will unite our school by creating a shared vision, purpose, and direction. in the body, i will use three main points that describe the different avenues the students can take: through a variety of clubs, through a special event, or through an awareness week. i will provide evidence about other towns that have unity activities and the kinds of events that they include. pictures will illustrate my three main points in action. for the ending, i will restate the main idea in a new way and pose a question to keep the audience thinking. 

the underlined phrase is an example of : understatment