Battleborn is a huge unsolved mystery despite the HUGE amount of games (dead game) and card packs on the secondary market, there does not seem to be a full checklist online that I can find even for the UK version. Here are all the details I know and will probably make a post on the Battleborn Reddit later to see if I can get any feedback from there.
First, there appears to be 31 cards in the set. 25 character cards, of which 2 are exclusive to the game releases: Deande and Toby. And the remaining 6 cards are puzzle or mosiac cards. The packs that come with the games have an item number BATTLEBORN/CARDS2/* where CARDS2 indicate that the pack has 2 cards, and the * is the region identifier. The promo packs that came from retail have CARDS4 printed on them. The packs themselves indicate the set is 31 cards.
Also reading online, the promo packs did not have a random assortment, rather they have a set assortment but the collation of packs to boxes or cases (that were shipped to stores) was not done as you'd expect. Meaning huge amounts of people could only find cards 1-15,24,25 while others were able to find 16-23 but not 1-15. And this seems to be primarily a UK/ENG issue where UK people were resorting to get the cards from other countries to complete their set.
UK (ENG) cards are numbered 1-25 for the character cards. I was not able to find a back image of the mosiac cards to know if they are numbered. As noted, cards 24 (Deande) and 25 (Toby) are exclusive to the CARDS2 pack from the games. Besides the UK games, the BE/NL and Italian English imports came with the ENG cards.
Australia has their own CARDS2/AUS packs and presumably CARDS4/AUS packs. Unable to find back images, cannot confirm if cards are numbered or if they are the ENG cards or AUS cards.
Germany has CARDS2/GER and CARDS4/GER packs. The character cards are not numbered, are GER cards and 2 have been identified. Besides the DE games, the AT/CH releases have the GER cards.
Spain has CARDS2/SPA packs and presumably CARDS4/SPA packs. The character cards are not numbered, are SPA cards and 4 have been identified.
Italy has CARDS2/ITA packs and presumably CARDS4/ITA packs. Unable to find back images to know if cards are numbered, 2 cards have been identified.
Poland appears to have CARDS2/ENG packs included with the games but I have not yet confirmed this.
Russia has a PC version with the cards label, but unfortunately due to current world events, researching this is almost impossible. For example, Avito is blocking access from outside Russia. So right now it is unknown what cards come with the Russian versions or if there is a Russian set.
These countries were only based on what regions already had game releases documented for, with the exception of Austria which I found by accident. There may yet be other regional releases beyond this that have the card label but I don't think I'm going to search the world for this game.
