If I am two give two major factors why I stick onto an anime on its first episodes, then I’ll say that it is the animation and the opening music.
Yes, we all know that poor animation would lead to leaving anime viewers. A great manga adapted into an anime but with poor animation gets a handy number of negative reviews because of its visual score.
The opening song should always make a great dance with the genre of the anime. I know that it is not just me how loved the Magic Knights Rayearth’s first ever opening song. The intensity never dies just like in the first opening song of Pokemon.
Going back to the third season stuff, I think the OVA of Magic Knight Rayearth is quite enough to give everyone a hint of what happened on its first episode down to its second episode. Oh come on, you are not the only one hoping for a trailing season but it is the end. Every story ends, we all know that.