Which season totally caught you off guard? (For better or worse)

I just finished the Prime Empire saga, and I'll be honest, o went into it with some low expectations. I thought the ninja suits looked kind of mid, and the fact that they barely used their elemental powers (which is literally my favorite part of the show) really bugged me at first. But mate, was I wrong. It's now one of my favorite seasons. The ending was amazing, the characters were solid, and those deep-cut references like Airjitzu and the Triple Tiger Sashay were the icing on the cake....