Hello,
First of all, i want to make sure we both are working in the same context. With the game Castlevania, without any manual adjustment. On my side, the screen is segmented as follow:
https://goo.gl/photos/PQL3Zt4DyPZkN4Hv7
I would like to repeat some info:
- The engine won't touch any pattern created by user
- By using Create, Merge operation you will created a new shape pattern and removing certain patterns in the process.
- Because of that after making those operations, you should forward the game some frames with the button > and >> so that the screen reflects the new, just changed pattern set and you can avoid the error message box.
- With your "demon" example, this is not your just created pattern but 3dnes had also created another pattern containing both the demon and the NPC. To separate the two shapes just manually create the demon pattern and if the mixed pattern still appears on the screen just select and remove it.
- I will continue to investigate the problem but i believe many things that you had observed are just normal behaviors of 3DNes, not bug or error.
- Please make sure to read carefully my explanation and if something isn't very clear just ask.