Luke

You know my biggest pet peeve with the green with evil arc is the serious lack of character development, other than Jason. I would even go as far as to say it shows how the rangers lack any will power, again minus Jason.

Over five episodes we learn that Tommy is good at karate, and that he is willing to beat up two kids who are drastically weaker then him just to impress Kimberly. We learn that Kimberly can't focus on any important matters at hand if her personal life isn't perfect. We learn that the rangers could survive just fine without Trini. Billy is smart like we already knew, and arguably held up the best out of the team without Jason. And finally I find it a little shocking, but Zach is willing, and almost encouraging that the rangers lost, and it's time to give up.
Jason is the only character who never gave up, and actually pulled his team back from the brink of defeat. While we always knew that Jason was the leader of the group, he never really showed a whole lot until this story arc, but without him the rangers were incapable of doing basically anything on their own. Just my two cents.