Penna's defining role stems from her protective relationship with her younger sister Parona. When the Yanome selected their village to provide a sacrifice to the Oniguma, Penna intervened upon hearing the arrival bells. She devised a plan to safeguard Parona by luring her into the forest under the pretense of a game, directly preventing Parona's selection. After several days, Parona returned to find Penna missing, with villagers confirming her absence. The context established that Penna had been taken as the sacrifice in Parona's place, cementing her legacy as a figure who sacrificed herself for her sister's safety.