The Undefeated Enemy

Everything's all fine and good for them until a certain somebody had to come along and ruin everything.

The opponent who the Hero or Main must face who has a perfect record and very good reputation among their fans. If we can get a look at them in action, we'll see them destroying their rivals without breaking a sweat. The protagonist who has to take them on is intimidated by this, but they must push on and face their biggest challenge yet. At first, it's a Strong v Weak match and the audience (not us) doesn't believe in our character at all. But as Plot Armor is on their side, they most likely win the game using their God-Send Skills and crush their foe's record and rep. The Undefeated Enemy might report them for hacking and violently demand a rematch after this undesirable outcome.