Ok here’s a short tutorial on how to use the image outputted by the creator and combine it with existing troop art work.
Setup
Step 1: Get GIMP if you don’t have it. https://www.gimp.org/ Download button is there on the main page.
Step 2: Create your troop in the creator and save it.
Step 3: Open the saved image in GIMP.
Spell Steps
Step 1: Find your desired spell graphic from the game files. They can be found in your GoW install folder, usually here:
\Steam\steamapps\common\Gems of War\res\Graphics\3\Spells\Cards
Step 2: Drag the image you want from windows explorer over on to the open GIMP window.
Step 3: Move the image into the correct position with the move tool (the circled icon on the right).
Step 4: Make sure you reorder the layers (click and drag) so that the spell is below the base image (circled on the left).
Troop Steps
Step 1: Find your desired troop graphic from the game files. They can be found in your GoW install folder, usually here:
\Steam\steamapps\common\Gems of War\res\Graphics\3\Troops\Cards (note I’ve used the Cards folder for this example, the images in the Troops folder could also work, but might require some resizing).
Step 2: Drag the image you want from windows explorer over on to the open GIMP window.
Step 3: Now the troop art has the extra black area which we’ll need to remove or else it will show off the bottom of the card. We didn’t need to do this for the spell image as the black parts got covered by the card image completely. Using the Crop tool (circled on the upper right) select the area of the troop you want to use. Make sure the Current Layer Only option is ticked (circled on the lower right) or else you’ll be cropping the whole image. When ready, hit Enter or Click on the image to crop.
Step 4: Move the image into place with the move tool (circled on the right) and move it’s layer down below the base card. (Circled on the left)
Exporting
Step 1: Now we’re done and to save this as a PNG, go to File → Export As… to change the name of the file. Or just use File → Export to to overwrite your original image. NOTE: Saving the image using the usual File → Save will save the image in GIMP format, which won’t help much, unless you want to change stuff later.
Hope this helps some people!