Take is an instant ability and completes in the phase in which it chooses a target. Instant abilities cannot be negated after the phase in which they complete, so negating Turn to Egypt does nothing.
Discarding Turn to Egypt, on the other hand, ends the take. Which either immediately returns the Hero to the previous territory or just returns the Hero to that territory after battle, as if you had banded it in. The Hero is most likely returned to the previous territory immediately, similar to a basic take being a potential battle winner.
