I didn't really like the fourth season, the one with "The Hollow". I don't really care for it when they overplay the witchcraft stuff that much. We were told that their mother was the most powerful witch of all time. And the Michaelsons found a way to defeat her. Anyway, the magic didn't dominate them in the first couple of seasons.

Writers need crises in order to create tension in the show. I guess that is why they decided to introduce an even more powerful witch than their mother: the Hollow. But it seems like a cheap trick to me. Whatever the siblings do, the witch finds a way to avoid being defeated by them. The Hollow is a nebulous, mysterious, evil person who, from her childhood onward, killed her own people and whomever else she needed to kill in order to gain more and more power.
I don't like them facing a purely evil enemy who seemingly cannot be defeated. The Hollow possessed Hope. The Michaelson siblings finally saved Hope when Vincent somehow split the evil magic of the Hollow and put some of it within the siblings and banished them from being near Hope or one another. So they didn't really defeat the evil power. It still plagues them now since Hope wound up taking that magic back into herself and is being killed by it.

I am liking season five presently. I like seasons one and two as well. Season three is my second least favorite.