I guess I can see what is going to happen. They go with HeroYuuya and get blasted one by one by him. Ark finds out and becomes broken. Ark probably tries to fight back in anger but loses in front of them.
OR
They refuse to go with HeroYuuya and he throws a fit and schemes on taking them with him
Yuuya is summoned and told he is the hero and upon his summoning the Demon King is created, Hero Yuuya’s companions
Hero Yuuya looks to be evil (to me)
Cuts away to Ark(the MC) and the introduction of his Stepsis, Noona, and 2 childhood friends. They get hero skills while Ark gets farming skill.