Team Galactic Eterna Building
A Team Galactic building located somewhere in an Arid Highlands biome. You will be able to find Jupiter, a pre-requisite to Saturn in the Team Galactic HQ.
Locate Structure Command
/locate structure cobbleverse:eterna_buildingGuide
To find the nearest location, craft a Secret Key and place it in any regional cartography table with an empty map. Otherwise, you can find the eterna building in an arid highlands biome.

Find this building somewhere in the arid highlands or using the map. It will look like this:

On the first floor, you will find a Team Galactic Recruit, as well as a door and stairs.
Behind the door, you will be in what looks to be a lounge area. In the connected room, there is a Team Galactic Employee and a chest behind some bookshelves.
The second floor starts you out in what looks like a server room. Here you can find 2 Zygarde Cells and a Team Galactic Engineer.
Behind the iron door is a hallway with a hidden cabinet on the right of the stairs and a Team Galactic Researcher at the end of the hallway.
On the third floor, you will see the researching floor of this building. Here you will be able to find a Team Rocket Scientist
On the fourth, you will see a door, bubble elevator and a painting.

Behind the painting is a hidden room. Inside, there is a chest that contains Rotom parts.
The other room seems to be an armory. Go up the bubble elevator after this.

At the top of the bubble elevator, you can fight Jupiter, which you need to do as a pre-requisite to fighting Saturn at the Team Galactic HQ. Behind one of the G's, there is a chest that can be looted.
Beating Jupiter here will drop an Acuity Proof which can be put in a regional cartography table with an empty map to find Lake Acuity, where Uxie lives.
Team Matchup Analysis
Create a team in Team BuilderSelect one of your teams to see type matchup analysis
against all trainers at this location