Woodland Mansion That Is In A Dark Forest And A Pale Garden

not even rare mate
Woodland Mansions generate in Dark Oak Forests, and Pale Gardens always Generate Next to one.

Not every dark forest has a pale garden next to it. Pale gardens can generate next to other biomes.

It's called a roofed forest, not a dark forest

They used to be called roofed forests, but now they're called dark forests.