Event editing: Invisible NPC like in Narshe?

I tried expanding my rom, but I've ran into the following problem (man, I feel stupid for having to ask so many things, lol):

Don't feel stupid, the way I coded this is super inintuitive lol. Once your ROM is expanded, open it in FF6LE and go to the Expansion Window. Choose a folder for the XML file different from the default one and then click "Apply changes". The "Expand maps" button should enable itself and you should be able to expand the data in the banks specified. After expanding maps the "Expand chests" button should enable itself (this is optional and you don't need it to work with expanded maps. You can come back later to expand chests at any moment). Don't forget to save your ROM after or the expansion will not be saved. I should really change how it is done but I've been lazy to do so..

I should also add that there's no coming back once the expansion is done. Gi Nattak has been using this version for RotDS so there shouldn't be any problem though.

Ah, thanks man, now I got it working!  
I've already encountered my custom Czar Dragon int the very next room behind my unsealed door just to see if this new event worked properly too, and after a little bit of tweaking it did. Next steps will be to gradually add more rooms to the dungeon to see how much I can make of it, and finally I'm going to replay the entire game from beginning to end to make sure that nothing else was screwed up accidentally.