Touga's ghost in "Adolescence of Utena" was trying to take Utena with him, killing her in the process, instead of helping her out. And it wasn't even Touga as a character, but rather as the idea of "chivalry" or being a hero.
Yeah, when Touga was alive, he saved Juri because he was a decent guy, but he also did it in a dangerous way because he had no attachment to life and wanted to die. In reality, knights don't exist. They're an ideal. There are no knights. There are, however, people who seek to help others and who also need help. If you seek to be a knight, you end up taking agency away from the people you try to "save" and damaging yourself under impossible standards. And the ghost of chivalry/the idea of the hero sought to drown Utena in the guilt of not being able to live up to those standards and in being stuck always trying to do so while burying her own humanity. She realizes this and tenderly dismisses the idea by her own choice with a goodbye kiss because, after all, she recognizes how it helped her at the time. But, like any self-damaging coping mechanism, it hurts her, and that's why she lets it go.
