The above video is a sketch from a comedy show which perfectly sums up a problem in many roleplaying games.
One of the characters has a special ability which is waaay more powerful than the other. BMX bandit’s mad BMX skills are rendered useless by Angel Summoner’s powers. He might as well not be there. TVtropes calls this “Overshadowed by awesome”, in RP it’s sometimes called godmodding.
A special ability which is way too powerful
Angel Summoner’s ability to just do anything in a blink of an eye removes any drama from the storyline. It’s over too quickly. There’s another article about this – All-powerful characters are boring. You can resolve this by giving your character flaws, and penalties for using their abilities.
Can you think of other good examples that demonstrate these issues, maybe you’ve had them in your own game?