Koji Kitao is probably still the all-timer I suppose. He was very weirdly promoted to Yokozuna without actually winning a tournament in, by sumo's conservative standards, maybe the biggest gamble they ever took. It backfired spectacularly. He finished runner up a few more times, never managed to win one. Then there was an incident where a bunch of the junior wrestlers in the stable refused to serve under him because he was an abusive prick, and if that was brought up in sumo in the 80's I can on