The two demons (yes those two guys with that angry fat dude this chapter) will join up with that Fernando guy.
Things happened (didn't read that raw)
They'll try to kill Mercedia and steal her credit about finding the sealed door.
But Theo rescued her group, and they came back to report to the princess.
Theo also point out "btw, those two guys behind you, they're demons"
Fernando panic, two demons reveal themselves, proceed into 3 separate 1 v 1.
Mercedia easily rekt Fernando before the chapter even ends.