Although it doesn't try to do something as radical as World Seeker, One Piece: Pirate Warriors 4 is arguably just as great by sticking to the satisfying Warriors gameplay loop. One Piece fans will adore it even with its condensed story-telling, but it's also great for people with a casual interest in the series. It's easily the strongest title in the series so far, and a great bit of mindless fun in the wonderful One Piece world.
The bottom line is this: the gameplay, abundance of cards, and fan service mean that those looking for a virtual Yu-Gi-Oh! card game experience have come to the right place. The overwhelming learning curve and lack of production values means that it's probably not the best way for newcomers to experience the series though.