Hi Guys, my name is Bruno AKA SaturnAR.
I'm currently working in SS SoTN translation from JAP to ENG (despite the fact I speak Spanish).
I know this is an old thread but hopefully I'll be able to discuss with you some things about SS SoTN. Most of things are drawn in VDP2 making thins quite harder to extract/analyze/patch.
For example, all menu screens are Tilemaps. All dialogs are tilemaps too. KANJI.FON (12x16px fixed width) is only used AFAIK, for some text during game's main menu. Font is compressed. 1 nibble defines the color of 3 pixels. ASCII.FON seems to use the same compression method but char size seems different (and interlaced?). I made a custom tool to extract both: KANJI.FON and ASCII.FON.
Dialogs are stored in several files. Associated .CHR stores tiles ("characters" in SS VDP2 manual) data. Each tile is in this case 8x8px and 4bpp (palette). Only 2 colors of the possible16 are used: black/transparent and 0xE738 (ABGR1555 = 0xE738 RGB888 0xC0C8C8). Several tile sets can be stored in a single .CHR file.
.PTN (Pattern?) stores tilemaps. Each .PTN can store several tilemaps. Each XXX.CHR contains tile data for the associated XXX.PTN file. Data stored is optimized, using sometimes one tilemap line for more than one game dialog line.
I've also made a tool for extracting all the dialogs with success.
.PRG seems to be program files (SH2 code mostly with, maybe, some strings).
Dracula X main title logo is also Tiled. In this case palette is 8bit (256 color palette). Tiles are loaded starting from absolute address 0x05E18000 and image is stored (If I remember right) around 0x05E40000. Similar case for Data Select Screens, etc.
I have not researched items descriptions / inventory. I do saw that all static info is stored in VDP2 too. If I have to guess, as a tilemap, again.
If you, Gemini, could give me the graphics you used for the PSX translation, you would save me lots of time.