Responses
If I had to take a guess, I would say enough of level difference makes damage delt null. In one of the first chapters lv.40-50 bandits attack lv.99 MC and she takes 0 damage. So it might be just connected to how the Alexander's Law works (but honestly idfk).
i think it's about the prophecy
I think the combat unlocks their level cap.
Seems a bit of a waste to have all other eligible heroes KILLED while only 4 remain. Yeah, I get it, only the best can fight the Witch. But like...what about all the other terrible things in the world? Does the witch have followers? Maybe more than 4 people can fight her? IDK man, seeing a group of like 100 lvl 99s going after someone is a lot scarier than just 4.