I think Grodus is one of the best villains that the Mario series has ever seen. Grodus, in my opinion, had pretty much all the qualities that make a good villain; He was cold, ruthless, sadistic, and power-hungry, etc. He didn't have an ounce of sympathy or concern for anybody, not even his own henchmen (since he treated them like crap, but that only contributes to his character as a cruel and merciless villain). Other things I like about him are the fact that he's manipulative (as he demonstrated during the events of Chapter 7, where he tricked Lord Crump into guarding the last Crystal Star for him), he's psychotic, and he has the most hilarious maniacal laughter I've seen or heard from any villain. Also, let's not forget the part where he used Peach as a shield, threatening to kill her if Mario and his partners refused to surrender, which is another thing that clearly demonstrated just how evil this guy was. I personally wouldn't mind seeing him in another game. Unfortunately, that's never going to happen, since Nintendo always insists on permanently removing every main villain in the series except for Bowser. In fact, I think Grodus is a far better villain than Bowser ever was, but maybe that's just me.