Basically what I mean is if the character's actions/behavior throughout the series causes any form of controversy that 'divides' the show's fandom into sides where one side agrues in favor of the character while the other against them. They may be popular however their 'hate side' might rival their fanbase thus causing controversy whenever their name is even mentioned. The more arguments abt them, the more controversial they are.

not as far as i can tell. most people like lelouch and those who don't/are neutral don't really bother talking about him, rarely see a blowout between two people with opposite opinions about him

I'm kinda torn between yes and somewhat when it comes to my favorite character so yeah, I might change my answer ~

The majority of those who know him like him, and the few that don't are usually subtle about it.

lol @ Sasuke not being controversial