[Dr Kain]

I've come to realize that the differences between 80s and 90s Sentai are like the differences between Silver Age DC and Silver Age Marvel. Like DC, the 80s series were more concerned with individual episode plots and giving the heroes different abilities to distinquish themselves rather than having any sort of character growth. On the other hand, 90s Sentai was like Marvel in the way that characterization mattered over episodic plots, so series became more character oriented as they were the driving force for the series as a whole.