Even in the world of Runeterra there are pejoratives which people use. What is "cancer"?

Wait, is Runeterra even still cannon?... w/e

#Before you read any of the comments previously posted! Scroll down type into the reply box and give your opinion on the traits that make a champion "cancer", or the traits which would be characterized as "cancer", and then take the time to read the comments. Note: you don't need to submit the comment, just put your opinion down before you read someone else's definition.

I really want to get down to the bottom of what people mean when they say "cancer", because despite using the same terminology, there are far differing opinions on what categorizes something, and which champions, as such. Politics man...

Please upvote for visibility and to get more people into this experiment/discussion. [slayer-jinx-catface]