An ilias is a specific personality type often only found in upper middle class to upper class suburbs on large american cities. Ilias' tend to by greedy, condencending, arrogant, delusional, and often carry a holier than thou attitude to extreme proportions. What seperates an Ilias from an actual douchebag, narcissist, or arrogant person is that an ilias will rarely be able to back up any of claims, and will resort to ad-hominem attacks concerning your lack of material wealth, when confronted by any facts arguing against his/her delusionment.
me: Dude that guy over there thinks he's Mr. Jacked mcJacked, and can get into investment banking, trading, or consulting, and harvard despite having a less than 3.0 gpa in high school.
friend: Ya dude, he's as ilias as they get.