Batman, Gazelle, and some others. I think what took the cake for me was the Kaido one shot. And it wasn't because Luffy got one shot, it was because I knew it was just bullshit to get Luffy away from everyone else. Later on we see a broken bodied zoro and Law take the same hit from hybrid Kaido and remain conscious. I knew it back then but it confirmed it for me that Oda downplayed Luffy just for story progression when it was not necessary. And then we had to sit through Luffy getting pestered in Udon by fodder. It was the disrespect that was shown to Luffy that shows that Oda still sees him as an underdog and that made me stop reading for a while.