Current questions and answers regarding the map editor.

First, you need to create this dungeon. To do this, click on "tiles" (to the right of "objects," this is the tab where you click on an object and place it on the map), then click on "lower," select the x3 brush, and then start removing the walls in the dungeon.
Regarding the selection of walls, this is the rightmost tab after "tiles" - "craigs," then choose the type of wall you need, and start drawing on the regular walls; they will change.
Crystals are located in "objects" under "subterrain objects."