I was watching "Titans" S2E5, minute 33 in found a sentence that make me think about the shall usage.
"It is you they are looking for. But it is he they shall find."
Besides the sentence has not sense for me, I can't understand the usage of shall on that situation. Why he don't use will instead?
I guess "shall" usage is one of the hardest stuff to understand to which are learning English.
Can anyone explain me?