Well, if I have longer time to finish the game, perhaps modular 3D assets and in-Godot-editor level design would be more appropriate and can give better realtime feedback. But since it's already day 2 and I still have a lot of homework to do, then Blender is my only reliable buddy here.

I want to create a cult mansion and basement with puzzles (if I have time), so far so good... I guess... not having high expectation on the texture. Noise map would be enough for now. And yeah, I simply create walls and tiles in modular way but it's not that kind of modular...