This term commonly used in baking can actually be your best card in your pack albeit a little boring and simple.
Vanilla
Nami/Brook/Jinbe/Sanji
Brook (only one with only 1 leader)
The first ever promo card released in the OPTCG had this keyword although you had to attach 2 DON!! card before getting ahead of yourself
Rush
EB04-038 Rosinante & Law
Special/Wisdom
An 8c 8k that played 4 specific characters from your trash by going DON -1 and trashing 2 cards was played in Reiju, and would also be appropriate to do if you catch a cheater or slow player at a regional
Vinsmoke Judge call
This little card given out during the op14 pre-release is only playable in a single deck yet costed a big sum of money
Girl
Yamato/Ace/Garp/Sengoku
Garp ( not an op16 leader)
This deck is the first ever world champion of the game. Although we could have told you that since it was on fire and mirrors plagued the competitive scene
EB01-021 - Hannyabal
Slash
This EB04 Common gave UP Sanji the ability to play Sanji from trash is also the best card in RP Law allowing him to reramp for free and is also a 2k
Stealth Black Maria
This pre-release common was almost double as good in attack as anything else in the set. It packed quite a bite boosting your leader to 6000
Holly
Charlotte Pudding/Nami/Gecko Moria/ Borsalino
Borsalino (Not a banned card but is pair banned)
Being the first of its kind, this once 50$ meta staple's effect bottom decked its self to give -3000 to a character. It's effect was so good it was reprinted thrice!
OP01-033 Izo
Ranged
This archetype, originally released in OP05, was BDIF 8 sets later, allowing you to rearrange your life cards while being a 4k counter event
Celestial Dragon King
This leader was the defacto choice in pre-release if Rainbow Luffy wasn't played. If you weren't on this red leader you were cooked!
Red PRB01 Sanji
Fourtricks/Robson/Nola/Salome
Fourtricks (Animal Pirate not "Animal)
Fourtricks (Animal Pirate not "Animal)
This was the first draw 2 trigger in the game. It was so good that op03 U Nami ran it despite not being able to use the [Main] effect
Impel down all-stars
ST24-002 Kid & Killer
Slash/Special
The return of this crew was all thanks to Don Krieg's printing in OP14 doubles as a 2k counter in the new BY Teach deck whose trigger draws a card and plays out any 1c character from trash
Black Caterina Devon (Black Cat Pirates)
This set’s pre-release had good blockers, but your opponent could've pulled the king of closing out the game from one of the case hit slots rendering them useless
OP13/Carrying on his will
Tony Tony Chopper/Edward Newgate/Trafalgar Law/Shanks
Edward Newgate ( only one without a card in each color)
Complete removal protection existed all the way back in OP02. But required you to play this card: a 3c 4k Mink and have all your don rested.
Inuarashi
OP02-082 Byrnndi World
Strike
A frowned-upon win employed by yellow decks going double borsa on the last turn that is also a 4k counter event if there is an 8000 on board
Winning on time for the counterattack