S1·E49 The Final Victor

As Heero and Zechs come to the end of their final duel, the battleship Libra and Peacemillion descend upon the earth threatening to engulf the world in a never ending winter.... Meanwhile Trowa helps out the wounded Quatre, and Duo delivers the "lords of plague" to peacemillion, in the hopes of averting the tradgedy of the battleships plunge.