Each battle costs one Event Stamina, but you only lose Event Stamina when you win , so you should always attempt the highest difficulty you can beat
OP-16 The Time of Battle is the next major One Piece Card Game release after OP-15, and it has the exact ingredients collectors usually chase: a Marineford / Summit War theme, six new Leaders, Secret Rares for Ace and Blackbeard, and a Super Parallel lineup centered on the three Admirals
The deck wants to build a massive engine with Kilo, Apogee Mindand win via alternate conditions like Darksteel Reactor
A 15/15 with flying, annihilator 6, and an extra turn on cast closes games immediately
Emearld/Amethyst This is a strong matchup for you as your opponents characters will largely be fodder against your powerful retinue of songs