In which episode did Petra's attack giant die?

Petra died in episode 2 1 of this cartoon.

In the play, Petra was attacked by the giant when she failed to catch her and retreated. In order to protect Allen, she fought against the Giantess (intelligent species, whose ontology is Anileonard, 104, the fourth place) together with Oulu and Evodo. After poking the giant's eyes blind, she didn't have time to adjust her posture because of the sadness of losing her companion and not knowing that the other party could recover partially. As a result, the giant woman who recovered one eye first kicked off her spine and died.

The Attacking Giant is a Japanese cartoon, written by Lushan Chuang. Comics tell the story of human beings struggling with giants for survival.