It’s OK; but the plot doesn’t feel like it resolved very smoothly. It’s like the writers got to the big showdown at the theater and went, “OH CRAP WE ONLY HAVE FIVE MINUTES LEFT!”
Merlin showed up and my reaction was, “oh hey, it’s Eric Idle!” Really appropriate for him to be a wizard again as he also voiced Rincewind in the Discworld games. And actually, I’m not the only one to have noticed this, Merlin even looks quite similar to Terry Pratchett.