When playing Akachi, if you put his "Spirit-Speaker" signature card on the table, there's a stack trace in the logs :

I looked at the action.py script around line 550, and understood : this code tries to figure out how many ressource token to put on the card, but fails if no digit are found inside "uses (...)".

I'm sorry I don't write python code so I cannot help fixing it, but it seems there's just an 'else' clause missing.