His ability to use Conqueror's Haki has been common knowledge since his time on Fish-Man Island, but following his battle with Kaido on Wano, his mastery over the technique has reached all-new heights.

Source: https://www.cbr.com/one-piece-conquerors-haki-users-ranked/

Queen Otohime's method of ruling proved effective during One Piece's Fish-Man Island arc, and there's a valuable lesson or two to take from it.

Source: https://www.cbr.com/one-piece-queen-otohime-fishman-island-lessons-acceptance-empathy/