Card Captor Sakura - episode 45

 As a result of Sakura's last successful effort, Kero briefly loses conscience and lies in a state of suspected animation. He's soon involved in a pair of wings giving off magical aura. Out issues his true form, and something more closely resembling a Guardian Beast. Actually, it's just a tiger lookalike with guards and pads on his taut body. He also speaks in a serious voice to boot, with a cryptical tone and no-nonsense attitude to boot. Concommitantly with everything is Julian fainting and an angel-like man emerging from where he was standing. He introduces himself as You-Ai, and it soon comes to light that Clow Reed always meant for there to be two guardians to the Clow Card Book, one being Kero, short for Keroberus. The other is the angelic apparition who clears up on Sakura's remaining doubts and tells to get ready for the Final Judgement is about to start. Having seen for himself all the requirements met for the fateful event to unfold, You-Ai wants to immediately put to test the young duo's aptitude in the eyes of the Clow Reed. After a few more words of warning, announces that the Final Judgement is about to commence, with Kero nearby and yet unable to help his understudy for the first time ever since their first encounter. In typical anime villain form, You-Ai taunts Sakura and Lee before personally engaging them in a one-on-one skirmish. Predictably, Lee loses and it's up to Sakura to face up to him and prove herself worthy of the honour of Keroberus' trust.