This Summoner Class Card was posted in the Map Sprites/Class Cards repository, but from what I understand the creator wasn’t mentioned. Here is the class card in question:
Does anyone know who made this card and if it’s free to use with credit? If not, are there any other Summoner class cards that are free to use with credit?
You can apply that logic to anything in these sorts of repositories. If it’s only posted in someone’s personal thread, then you should contact the creator and ask them.