Matchup notes
Short notes on how the leaders people keep registering actually play into each other. Leader text is the printed effect. The only pairing table on this site with counted games is which decks beat Mihawk. Everything else here is a play pattern, not a win rate.
Mihawk into Slash
Green Mihawk is 5 life / 5000 and gains +1000 power when the opposing leader is Slash. Rocks D. Xebec is Slash, so Mihawk is a 6000 leader in that seat before any DON!!. Once per turn, with a 5-cost Character in play, he can rest one of his cards, set up to three DON!! active, and then he cannot play more Characters that turn. The plan is play the body, untap DON!!, and spend them on events and attacks.
The counted games are on the Mihawk page: across that write-up he is favored into Rocks and behind into Robin, Ace, and Sabo. Decks that beat him race life or present threats his rest does not answer. Decks that lose try to win a rest war.
Rocks into the rest of the room
Rocks attacks, may trash a card, and draws two if the revealed card is Rocks Pirates. The list is a type deck, so the attack is the search. Curve, keeps, and the Slash problem versus Mihawk are on the Rocks strategy page.
Into leaders who are not taxing his Slash attribute, the game is whether he finds the even or odd line and still has the 10-cost Xebec. Into removal that clears the 6- and 7-cost bodies, he has to attack again and hope the top deck replaces them. He does not have a built-in answer to a wide board of 12-cost blockers.
Sabo
Sabo loses 1000 power while you have 4 or more life, and gives your leader and Characters +1000 once an 8-cost Character is in play. Early he is a 4000 leader if you are still at high life. The turn the 8-cost sticks, the whole board gets bigger. That is why the matchup is about sticking one big body, not about attacking with the leader on turn one. Curve and mulligan: Sabo strategy.
Into Mihawk he is one of the three decks the pairing page has ahead. Into a pure race he has to spend a turn on the 8-cost before the power buff exists, so a 4-life aggro leader can take the life he was trying to sit on.
Luffy & Ace
Luffy & Ace is 4 life / 6000. If you have a Character with 7000 or more base power, the leader loses 2000 power. On the opponent's turn, Portgas D. Ace and Monkey D. Luffy cards gain +3000 power. The deck hits hard and defends on the opponent's turn, then gets worse at blocking once the big bodies are down because the leader shrinks. Four life is the clock. It is the leader to race with, and the leader that struggles once the opponent can ignore a 4000 body and hit life twice.
Black Luffy and Kaido
Black Luffy gives every one of your Characters with a cost of 12 or more Blocker. One rested 12-cost can catch a single attack. The way through is removal, or a wider swing than one blocker can take. Racing the leader before the 12s land is the other plan. Leaving two 12s up and attacking one at a time is how the game stalls.
Kaido can spend one DON!! when he attacks, or when your leader or a Character attacks him, to give one of your opponent's Characters −2000 power for the turn. He answers a rested attacker and he trims a blocker on his own swing. Power reduction is the whole trick. A leader who does not need to attack with Characters, or who replaces the body he just shrunk, is the awkward seat.