Telepathy

Although he does have some resistance to it, some characters with powerful enough telepathy are indeed able to influence Superman’s mind.

Whether it be by using telepathy to mind-control the Man of Steel, by using it to put him to sleep or by using it to make him experience horrific illusions, with enough telepathic force, his willpower can undoubtedly be overcome and his mind can definitely be overtaken.

More often than not, the Kryptonian hero shrugs off such powers, but there is no doubt that he can be beaten by it in various ways if conditions permit it, as he has been controlled numerous times (seriously, it’s like the most attempted trick in the book!).

Characters with enough telepathic oomph to have influenced Superman’s mind in the past include Manchester Black, Maxwell Lord, the Insect Queen, Martian Manhunter, Eclipso and Nudge.