Let me state first that i had a great expectations of 2nd season of this anime. The prequel provided great introduction to the world and left the story at fairly interesting point. That is why i don't fully understand this continuation. The 2nd season fails as a sequel up to a point that it could be even called a side story. No, maybe a GIANT filler fits it better.
All ideas and setups that made the 1st that much interesting are basically abandoned in this season. An entirely different set of allies and enemies. No more experience points and guilds, no ranks, no more adventures either. Out a freaking blue, due to some "forced" circumstances, the whole team forgets about their dreams and goals and decides to grow roots in one place for the whole 25 episodes. For those that expected some follow up of the main story it's a big disappointment.
Having that much in mind - Excellion became boring. This season defines the average. It doesn't leave a bad taste but definitely wouldn't feel like watch it again.