Cardcaptor Sakura

Sakura and the Appearance of Clow Reed (3x23)

:

Eriol reveals his true identity to Sakura and Syaoran to be the reincarnation of Clow Reed's spirit. He sets his final challenge: turn all of the remaining Clow cards into Sakura Cards or the world will remain in eternal sleep and darkness. Sakura manages to turn six of the eight cards into Sakura Cards except for the Light and Dark ones, because both cards are loyal to Clow Reed and she is not powerful enough. Kero and Yue both help out Sakura by embedding their power into her staff, however if Sakura still fails then they will remain asleep in the staff forever.