It is known that prior to the start of the series, Glimmer was defending Elberon from the Horde. Glimmer and Queen Angella quarrel over this issue in the show's first episode The Sword: Part 1. The Rebellion leadership assumed it was far from the fighting which is why Queen Angella posted Glimmer near there. When the village was attacked Glimmer engaged the Horde, against the Queen's orders.
In the episode "Flutterina", the townsfolk throw a party for Adora, Bow and Swift Wind for defeated the Horde attack. However, after distracting Adora and Swift Wind, the Horde invades Elberon and kidnaps all the villagers and Bow.
Flutterina was apparently able to avoid being captured and go with Adora to rescue the prisoners.
Frosta, Micah, Swift Wind, Netossa and Spinnerella went to check things out when they heard that the Horde was spotted near Elberon. When they arrived all the villagers were inside and acting really weird. Netossa chided Spinnerella for leaving her alone at the "party" and Spinnerella complained that "something weird" just happened to her. The villagers then closed the doors and strongly suggested the hero's stay and wait for the honored guest, Horde Prime. Then the villagers attacked their eyes turning green, revealing that they've been chipped in the same way Catra was. Swift Wind was able to safely knock out the villagers when he sensed his sacred bond to She-Ra, this allowed the hero's to escape without harming the villagers. But every single one of them was chipped.