[maximus_asinus]

It is essential you determine whether or not you're using Classic style, or Modern style tilesets before you continue taking advice. If you're taking the wrong advice, you're just making extra work for yourself.

FOR OFFLINE ONLY:

Instead of using 'addtiledef' for now, we'll focus of adding the tiledef manually:

Navigate to your 'Graal' folder. From there go to the 'Levels' folder, then the 'tiledefs' folder. Once this folder is open look for 'tiledefsOffline.txt', and open it.

Insert below:
TILESET NAME, PREFIX, TILE TYPE,0,0

TILESET NAME - the name of your tileset. For your case 'faze-tileset.png'
PREFIX - basically the name of the levels you want these tiles to work with. If you have a number of levels you want this to work with use a prefix like "faze_" at the beginning of the levels you want the tileset tied to, and then add "faze_" to where it says prefix (above).
TILE TYPE - '1' for Modern Style tiles, '0' for Classic.

Once you've added the line (with the modifications mentioned above), save the text file, and open the editor (if you did this with the editor open, simply close and reopen).