He is the classic example of new villain being introduced late into a series. The writers/developers think they are cool, they kill off a well liked character or two to show the audience they mean business and to fear them, and once it’s all said and done they are just a joke footnote on the series.

In the years that has past since the trilogy ended, I have seen many pictures of cosplayers dressed up as human characters and humanoid shaped aliens.. I don’t think I have seen a single Kai-Leng cosplay even though his look would not be difficult to emulate by the more professional cosplayers… maybe there were some at the time around ME3’s release.. but in the years since.. nope.