How many items are in the character maker?

• 3 body types: average, dainty and heavy in 10 colours each.
• 13 outfits in 5 different colours per body type.
• 11 hairstyles in 8 different colours per body type.
• 7 headgears in 5 different colours - only some modified for dainty body type because the rest fit all body types equally.
• 13 Accessories, some with different colours, some modified to match different body types, some not (as above)

If you don't account for different colours & body types the possible combinations are in the 10s of 1000s, if you do they're in the millions.

And can we easily modify the tool to add original assets?

Not at the moment. All of the character pieces are provided in the pack separated from each other (bodies, clothes, etc.) so you can edit them in another program to make your own characters - but the Character Maker itself has those pieces hard baked into it, so you can't add your own pieces to it. If that's something people would like I'll put it on the to-do list.

Are the characters from the tool designed to fit both the adventure tile set and the RPG one?

Yes they are both 16 x 16 in tile size and the characters are 16 x 16 too. Although, the adventure tile set specifically uses a GBC colour palette because it's sort of inspired by the GB Zelda games. Recolouring the sprites to match it wouldn't be too difficult though!