Master Duel Keys are obtained through cards, specifically Super or Ultra Rare ones
These illustrations are often more detailed and enhanced by light effects, distinguishing them visually from traditional cards
Still, once you get off-planet and start to explore other nearby celestial bodies, you soon discover there is more similarity to the turn-based monster fighting combat of the Pokemon series
Duel Monsters (including Capsule Monsters but excluding the Pyramid of Light film)
Putrid Imp is a single-black mana zombie imp that gains flying if you discard, and gets +1/+1 but cant block if you have seven or more cards in your graveyard
Representation from one game to the next will vary a bit, with it sounding like Final Fantasy VII, thanks to its impact on the franchise as a whole and the recent Remake trilogy, will be heavily featured