Kai leng just comes off as a tool. I guess they wanted sheperd to have a rival, but it falls flat. Instead of having a rival that develops over three all three games, he is just there. I actually find him such a poorly designed character, even without considering lump of coal's rage comics. He is so smug, like when he sends you the email saying how "the story of your life is almost over, and I will be there for the final chapter, your death." Tool. Another example of despite being paragon, I did the renegade quick event to stab him.