In the opening battle, when Persephone loses an eye saving Alexa from attack. She's thought dead for a moment, but Alexa's quiet "Persephone?"...Tara Strong conveys so much horror that Alexa must be feeling at someone potentially dying because of her ineptitude on the battlefield.
The fact that Hippolyta beheads her own son Thrax without even blinking an eye, seemingly just to hurt Ares. Ares actually begs Hippolyta not to harm their son before the beheading and remains devastated by his son's death for the entirety of the film.
A smaller one when Steve and Diana are flying towards the final battle and Steve (with his leg in the lasso's loop, explaining his honesty) admits that he adopted a womanizer persona for some time so that he wouldn't be hurt again and that his macho bravado is all a façade. Turns out he's a miserable low-level Stepford Smiler, and the viewer is left to imagine what happened.
Alexa's death because it comes completely out of nowhere, marking the start of Persephone's Face–Heel Turn. To happen to such a sweet character right after a Heartwarming Moment where Alexa took over guard duty for Diana, specifically to let the princess have a chance to compete in the tournament.
Ares seeing his son as an undead servant to Hades, who gleefully abuses Thrax in front of his father.
Hippolyta: You were given a life of peace and beauty!
Persephone: And denied one of families and children. Yes, Hippolyta. The Amazons are warriors. But we are women too.
Her line to the queen before their fight retroactively becomes this after the above scene.
"I'm sorry, my Queen. I never meant to fall in love."
Artemis and Alexa look as though they are going to fight on the battlefield together finally, but Ares returns the dead Amazons to the Underworld. Artemis cradles her sister's body for a moment until she vanishes.
