Penthesileia

Proclus Chrestomathia
The Aethiopis:

The Life of Achilles is followed by the five books of the Aethiopis, the work of Arctinus of Miletus. Their contents [include what] follows.

The Amazon, Penthesileia, the daughter of Ares and of Thracian race, comes to aid the Trojans, and, after showing great prowess, is killed by Achilles and buried by the Trojans.

Achilles then slays Thersites for abusing and reviling him for his supposed love for Penthesileia.

As a result a dispute arises amongst the Achaeans over the killing of Thersites, and Achilles sails to Lesbos; after sacrificing to Apollo, Artemis and Leto, he is purified from bloodshed by Odysseus.