In a new school

The following day after learning more about Chloe Klein, and the demons she had killed, Loki was now certain that this world was really in the midst of an invasion and only the higher-ups knew about it.

Based on his knowledge about demons they would not stop attacking until this world is destroyed. Even back in his old world when he and the others defeated the demon lords in charge of invading their world the demons did not stop coming. 

'I tried to go to their place and see if I can destroy them from the root, but their world... That place is not somewhere a human could survive.' 

Remembering the time he invaded the demon realm he didn't even get too far since that place was huge and had an incredible number of demons. Well, it was to be expected since the demon realm can invade multiple worlds.