The Superman of the comics and movies could outrun a bullet and was also impervious to them. That was always bad for the villains in the story. While we don’t read about bullets in the life of Jesus, if you read the Gospel of John, you’ll note several occasions where the opposition wanted to seize Him or stone Him, but was not able to because, “His time/hour had not yet come” (e.g., John 7:28-31; 8:12-20; 8:48-58). No one could take Jesus’s life (remember because He was sinless and not deserving of death), but He laid down His life and subjected Himself to a cruel death out of His great obedience to His Father and their great love for us to make it possible for the believer in Jesus to be “holy, blameless and beyond reproach” (Col 1:19-23). Superman always put the good and welfare of earthlings above his own. And so did Jesus. This qualifies Him as a superhero.