Planar Engineer
thank you tvance52 for explaining it
"how does it work"
There are 6 stationary, immobile units that have free rituals that allow you to select all the terrain tiles in the game. Terrain tiles are every possible site in the game: any type of city, magic site, academy, any planar tile, plains, forests…anything.
The first unit has the first 30 (or 40?) tiles, the next unit has the next 30 and so on. 1 of the units has an abilities to allow you to "scry" everything in the game at once, so you can see all planes. This enables you to place any terrain tile anywhere on the map.
Since the ritual cost is free, you can basically edit an entire map on Turn 1 if you would like.