Tips to Get Pavilion
Pavillion is a random building drop (chests and bosses) and a random map completion reward.
Ship merchant occasionally sells pavilions.
Also it’s easy to get pavillion at the annual auction 4-time.
So pavilion check decor chests. You might be able to preorder it off trade house as well. Decor chests off airship or via mystery swimmer boxes or porcelain chests.