Hi @Skiptron,
Currently, there isn’t an official editor for modifying existing cards. However, you can edit some stats yourself. To do this, open the file ./data/cards.json, where all stats are stored under the key desc.
If you’re looking to edit abilities or effects, you might be interested in the Ability Editor. Unfortunately, that feature is still in development and doesn’t have a demo version available yet, so you won’t be able to edit card abilities in the current version.
Please note that it’s a good idea to make a backup before making any changes in ./data/cards.json. Also, after you modify it, you may be banned from sharing save files and reporting bugs via the game. Before reporting any bugs on ITCH.io, please ensure they aren’t caused by your modifications.
Let me know if you have any other questions!