The Isekai genre wouldn't be what it is today without one or two foolish villains attempting to stop the summoned heroes, and falling in the process due to plot armor, or their own incompetence. These walking EXP bags are often part of larger entourages: Cults, Demon Lord Armies, or more often than not, corrupt and entitled nobles. Their incompetence has caused more than one problem in their own worlds, and it usually ends up being the major cause of death among third-rate villains in anime.