This is when a book / movie / story relies too heavily on a characters, usually the protagnoist being invincible, without faults, in command.
This quickly turns very tedious. There is no story development, there is little suspense because the Übermensch will never be beaten, will never make errors, will always conquer.
It usually also makes the supporting characters shallow as their main role is to adore the Übermensch. Every now and again a member of the supporting cast might question the Übermensch but this always leads to death, or punishment or something else vile.