Some of the neutral creatures are quite strong, and it's difficult to replenish your army, as the castle has a low unit production rate.
However, there are 2 libraries and 1 utopia, and they are game-changers. There was a lot of light magic, so I had to switch to dark magic, as legions of blue archers can't be defeated with light magic alone. You take them out one by one.
Regarding the AI, yes, it's weak, but on the other hand, where would they get an army if they suffer losses?
It gets repetitive towards the end, but that's the case with many games. As for the Mask, that's a strange comment - it has never been a good artifact; to be precise, it has always been a weak artifact - and here we are again :)
However, it's not clear why it needs a face change.