Nasuverse Mod. Can we make it happen?
If not, then which of the Nasuverse's works can we do?

U make it

I've only got lore on Fate/Stay Night. I also have next to no skill with Lua, nor do I have any spriting software, which brings me to my second point. What is usually used for spriting, anyway? And where can I find some tips on how to Lua.

Lua isn't necessary to code anything in CC. It just allows a greater range of functionality that allows you to do fancy things such as switch modes on a gun or something. Most of CC content is written purely in it's own language (.ini files) which is unique to the CC engine that data created. I personally use MSPaint xp for simple things but for more complex sprite work I usually use paint.net.

Problem is that I'm probably going to need that complex stuff to get as close to a true representation as I can.
Also, it would be nice if this could be a team effort, at the very least because I'm unable to secure a copy of Tsukihime.