A rekindled passion

It has been over an hour now and there was no sign of the twenty. While they were waiting, Ren told Arthur to stand underneath the waterfall and swing his dagger upstream. He needed to this while trying to make his mana burst outwards, cutting the waterfall in half. He would not be allowed to stop until he was able to do it. Unlike the last task, this one didn't have a time limit. 

'Well, the only way he's going to be able to cut that waterfall in half is if he could somehow utilize all of his mana into one burst. He doesn't really need to finish this test, I just want to see where his limits lay.'