About Midna...we don't know what she would have like to say to Link. Maybe she wanted to say: "Link...I'm sorry for all the trouble I got you into" or maybe "Link...I appologize for my rudeness, can you forgive me?" We assume she wanted to say: "Link...I love you" but we don't know that for sure. And in Zant's case I think it was revenge. Maybe Ganondorf had assured him he wouldn't die and Zant was convinced his true God was one who kept his word. So who knows? Maybe after Zant was killed by Midna he met the spirits who told him differently? Or maybe his eyes were finally opened? These are all theories but theories can be fun. I think Zant felt betrayed by Ganondorf and used his rage to finish him off.