one piece card game booster pack Game: (OP-11) – Asmodee UK 01] features reprints of popular cards from OP One Piece TCG Royal Blood

You could play a kind of Modular deck using Artifacts such as Arcbound Fiend and Arcbound Slith, since you get to shift those +1/+1 counters around when they die, and then Ratchet, Field Medic can bring them back

That really allows you to flood the board with potential game-ending damage, depending on what you hit with

Honest answer: very playable out of the box, but not optimized

Thing is, planeswalkers get their loyalty counters when they enter the battlefield as a replacement effect, but transforming does not count as entering the battlefield (that's why Sorin's regular transformation tells you to exile it, and then return it transformed)