So for those who are cought up with the Fairy Tail manga, there is a mind blowing foreshadowing in the biginning of the manga. We all know the Fairy Tail Festival when Laxus started a tournament to find out the strongest member. Well when Freed Justine put up the rune with the rules: no one else over 80 can leave, why couldn't Natsu and Gajeel pass through?
(Spoilers Alert) It turns out that they both are over 400 years old. because them and the other three first generation are from the past.
That right there is the biggest foreshadowing. To go soo far as to put such detail and depth into the story is amazing.