With the help of Yotsugi Ononoki, Koyomi and Mayoi were able to escape from the darkness. Within the ruins of the cram school that they escaped to, Shinobu is consulted about the darkness. She starts to speak of what happened 400 years ago.
monogatari-ep-15Monogatari Season 3 Episode 15
Monogatari Season 3 Episode 15
[46] Onimonogatari [2] Shinobu Time – Part 2