Willow the series went off the abyss just like some of the characters leap over the edge of the Shattered Sea in the final episode. The show never recovered and Disney cancelled it.
The final episode is ok, it is just derivative of these types of sorcery fantasy shows. Apart from the Lucasfilm IP, there is nothing original here.
Right off in the Immemorial City. You know that Airk has been possessed by the wicked Crone as he tries to persuade Elora and Kit that the Crone is not that bad.
The last battle is visually interesting but the characters have no finality. It is all lazily done.
Writer Jonathan Kasdan had plans for further seasons. This is hinted at the end of this finale but it will not happen.