The Godzilla variants go down to uncommon this time, and having two different Showcase styles, plus the Extended Art, means a whole lot to keep track of
Also, the set was a little high on artifact reanimation due to the theme being so central
It also has an absurd amount of loyalty for a three-mana planeswalker, so it's near-impossible to kill if it comes down in the first few turns
It is gold and only wants to go in very aggressive decks
A card like Approach of the Second Sun just needs to be cast twice, so its not that much of a Johnny card
The other matchup where Solemnity really shines is Infect, and while Infect has become less popular with the printing of Fatal Push and the banning of Gitaxian Probe, it's still around and could rise again in the future