Complex sentence: When they found it, they discovered a group of Pagumon living there instead who immediately proceeded to treat the DigiDestined as honored guests, saying that Pagumon are the fresh form of Koromon.
Split into simpler sentences: When they found it, they discovered a group of Pagumon living there instead. The Pagumon proceeded to treat the DigiDestined as honored guests, telling them that Pagumon are the fresh form of Koromon.