The missing people that Toivo's referring to are mentioned here: https://www.ingress-comic.com/comic/chapter-6-08/
Second, what Nikki is referring to about "what happened before at Aidan's temple" is this story that Aidan told from pages 5.08 until 5.11, where Derik was transforming the clerics into Beasts.
https://www.ingress-comic.com/comic/chapter-5-08/
https://www.ingress-comic.com/comic/chapter-5-11/