Coincidentally, I was just working on a small thing that addresses your question.
I've done some work with Megaman and Castlevania title screens. I always end up messing around with how the tiles are loaded to change the shape as needed. You will want to learn some basic ASM to get this sort of thing done. Other than that all I can say is that the debugging tools in FCEUX are gonna be your best friends for finding the data you need to get the job done.
Anywho. Decided to give the Akumajyou Densetsu translation a new title screen. I'm thinking of making some more changes to the graphics beyond this and maybe more.
I think some of the letters need a little bit more work.
Mock Up. Redrew letters based on CV1. The graphics have already been inserted, but I still need to rearrange the tiles a bit and update the tile attributes.
Rearranged the tiles, but accidentally over wrote the new palette data.