I don't own Lost Girl and never will. No copyright infringement intended.
Kenzi was completely sure of her decision and what she had to do. And she wasn't terrified of dying, a fact that surprised her. She knew it was the right thing – Bo may not like it, but that was okay. Kenzi was an adult who could what she wanted.
Kenzi missed Hale, but losing him had nothing to do with her choice to die. She just wants to do right by her best friend. Her motto is to say screw everyone else. What she did is unselfish, a truly good act.
And as she died, Kenzi truly had no regrets.
