I think Chapter Black was more interesting in concept but Sensui's Seikouki coming out of nowhere and Yusuke then being revived as a Demon Clansman with no prior foreshadowing ruined it. Dark Tournament was "safer" and less irksome as a result. Chapter Black was a bit more entertaining to watch though, because Sensui's psychotic character was more interesting than Toguro's anti-villain battle junkie gimmick.