rebecca one piece card game [Japanese] / レベッカ OP15-053 only TCG+ stores will carry it! Rebecca (Parallel) - Royal Blood

During your opponents turn, you get to perform any actions that you could normally do during your turn, but during your opponents instead

(2009-10-01) You shuffle your library if you search, even if you don't put any basic land cards into your hand

That does some wild stufffor example, it gets Marsh Flats back twice for actual land ramp in Orzhov, it lets you feed cards like Dusk Legion Zealot into a Warren Soultrader multiple times, or it wrings the most value possible from cards like Boromir, Warden of the Tower and Dauthi Voidwalker

In short, if you get the landfall trigger in your first main phase, your creatures wont untap for your actual combat phase once the extra combat steps finish

How would you upgrade this deck

And theres a big difference between problem permanents that actively help you win games and problem permanents that just stop everyone else from winning games