God Eater (2015) : 1x6

Lenka, Alisa, Kota and Sakuya are out on a mission to hunt two large-type Aragami known as Vajra when they encounter an unusual black Vajra that devours even its own species. This Vajra is ridiculously powerful and the 1st Unit ends up scattered. Lenka takes Alisa who has lost consciousness and escapes into an abandoned building. His God Arc is fractured and Lenka’s confidence takes a serious blow. Alisa, who also loses her God Arc in the fray, is overcome with terror as childhood memories of her parents being killed by the black Vajra come flooding back. But it’s not over for the battered and wounded duo as a pack of Ogretails threateningly advance toward them in the abandoned building where they sought refuge.