It's Triple Triad card game from FF series with 2hus and the gameplay is pretty much the same as the original game. AI knows what they're doing and it's both fair and challenging in hard difficulty.
I was gonna say "wait what about the theme," then I realized Final Fantasy itself is probably a living legend of our age at this point. When we talk about folklore and legends I often look at the ancient times, but what happened in the modern ages should probably be equally important so to speak. I'm not sure if that's your intention though.
Overall a decent card game with complete functionalities and cohesive arts from AI Mebius.