Agree with
@Sadistic Senpai . Kanjuro is too quiet and feels like he is reserved for something until now. I meant, Kinemon got a lot of focus and talked a lot. Raizo, who appeared latter than both Kinemon and Kanjuro, already got more focus and part in the story than Kanjuro.
Now I will try to debunk the other 2 popular candidates.
1. Carrot
Not sure if people are just trolling, but her being a traitor doesn't make sense, given her action and personality throughout WCI arc. She cried a lot already right after Pedro exploded himself, so it's understandable that she doesn't cry anymore now.
She's also very young and sounds very naive, as seen in WCI as I stated earlier. Her suddenly being a traitor is just a forced twist that feels out of character imo. Too young to play that kind of act.
Regarding why she doesn't get focus and becomes background rabbit again in Wano arc so far, well, let's hope it stays that way.
2. Shinobu
If Shinobu is actually the traitor, her action doesn't make sense. She saved half of Straw Hats, iirc also Heart Pirates and Okiku, from Kaido's borobreath which is otherwise instant game over for those characters. If she's the traitor she won't save them, and instead will save their own skin.
Her hating on Law is just usual misdirecting. The traitor also seems to be smart enough not to blow his/her cover until now, so with Shinobu openly hating Law I don't think it matches the traitor's portrayal of intelligence.