[k//eternal]

I'm betting that there's a bit of extra room in

Spoiler:

the existence of another Battler, and I think it's pretty likely that the other Battler is on the island. Since it was stated that Ushiromiya Battler isn't Asumu's son, the other Battler is probably a girl, and could be the older Ange.

Ange's destruction might have been a result of violating the use of red text by using it to tell a lie. There's little other reason she would have been destroyed just by confirming her identity.