The Pink Wall

The Pink Wall is a small room containing 18 Clefairy and 2 Cleffa at Level 100 located near the entrance of Mount Skylift.

They know the following moves: Light Screen, Reflect, Moonlight, and Minimize. Their ability Friend Guard allows them to take smaller amounts of damage with more allies around, as well as having Cute Charm to infatuate you (since some Clefairys and Cleffas are male, some are female) alongside having Light Screen to raise Special Defense of all the Clefairy and Cleffa and Reflect to raise Defense of all the Clefairy and Cleffa, hence why it is difficult.

Though there is a give up prompt, no items should be lost upon giving up.

Trivia

 * The best way is to go in with something that has Mold Breaker that can spam an Area Of Effect move (AOE), which will bypass Friend Guard; however, Cute Charm can still take effect, and Light Screen and Reflect will still reduce the amount of damage received. An idea would be Pinsir as it has the ability Mold Breaker, and with its family item, the Pinsir Sash, which allows its moves to not be affected by Light Screen or Reflect. Again however, Cute Charm can still be a problem.
 * The Pink Wall was originally located in the tent in Skit's Music Hall in the Delite Plaza.
 * The Pink Wall is meant to be a troll location and has no actual use or reward in clearing the area.