The thing is I can't help but think that Lord Zedd despite the fact he's one of the meanest and most powerful Power Rangers villains in history had one BIG problem- it was his replacement putties. I assume while he was conquering one planet after the other, he must just have been using the normal putties because he told Goldar that he had new ones. Yes he did and to think about it, they were stronger but they had one problem- one hit at the chest and poof!
Okay it's NOT easy to target the chest but the Power Rangers knew their secret that they didn't have to morph. Even a simple throw of a ball at their chests was enough to defeat them. Soon enough, these guys became easier than Rita's putties. One just hit- poof! Sadly many PR fans berated them for becoming too easy to defeat.
Funny that when Rita married Lord Zedd and the two were starting to like each other even when the potion was fading, that Rita didn't bother to redesign the putties even if Lord Zedd would have allowed her.