aww. sometimes with woman like that. it will ruin what good from the stroy. and a scheming one at that. well i hope not. there is to many story become annoying just because if there is a d*ck it need pu**y companion
So the sister awakened her hero thingy and her brother awakened his demon Lord kind a power? Well if that God or fate do, then this world pretty much like hajime or shieldbro one