No Mon Is an Island - S1.E37

The crew meet Zhuqiaomon the Digimon Sovereign. WarGrowlmon, Rapidmon and Taomon face him but are no match for him and Rapidmon's injuries from Chatsuramon leave him weakened and he is indicated to be slowly deleting throughout the episode as he flickers several times. Lopmon tries to help convince Zhuqiaomon to stop but fails and is nearly destroyed by him but WarGrowlmon protects her. Her cries summon Suzie (who was supposed to be watched by Guardromon but he misunderstood Kazu's orders). Rapidmon is defeated and reverts to a severely weakened Terriermon. Henry's determination causes him and Terriermon to BioMerge to MegaGargomon which heals Terriermon's injuries. MegaGargomon defeats and apparently destroys Zhuqiaomon along with his castle and everyone celebrates outside. Unfortunately, Zhuqiamon is revealed to have survived and comes back for revenge.