@RigobertoParedes
@J363
The demon general guy who told the girl to betray the humans was a member of the MC´s party in the past and is in love with the demon king/ queen.
So if he were to trust the MC´s schoolmate he would be all over it helping them meet up because it increases the chance the MC wont mary the demon king so he can do it instead, they are alot alike in that regard honestly.
it was mentioned somewhere in the first 4 chapters that the demons attacked the humans first because the humans unsummoned the hero after he saved the world.
basically the demons and beastmen attacked the humans out of revenge for effectively " killing" the hero who saved everyone.
witch they allegedly did out of fear as they were afraid he would take over the kingdom according to the MC, but we cant really be sure on that just yet.
The humans however are 100 % ok with this war as it gives them a chance to expand the borders and because this gives them an excuse to summon heroes again.
it dont take a genius to suspect that they might "remove" them aswell once they stop being useful. ( i mean they booted the MC out of the castle for being useless day 1 )
So really the humans are the "bad guys" even if they are the one fighting a defensive war.
The demons and beastmen on the other hand are fighting the war over somewhat legit reasons, but its still petty as fuck... not to mention impractical to start a war this soon.