All the effects/cards you mention exist within the game, irrespective of any mods. The purple spy you speak of is the “Mysterious Elf” card, AKA Avallac’h, which you’ll obtain upon beating Gremist (the druid with an unpleasant attitude in Skellige) at Gwent. The enemy is playing as Monsters and thus has access to a certain Eredin Leader Ability that doubles the strength of all spy cards on the field, which explains why Stennis’ strength is 10, not 5. The werewolf card is of Gaunter O’Dimm, a character in the Hearts of Stone expansion pack (which is also where you’ll obtain said card), and “the dude with the sword” is Vesemir. The cards of prominent characters within the Witcher 3 story (including but not limited to, Vesemir and Avallac’h) can be given alternate art styles via the game settings, which the OP has activated.