( and the one who’s easy to find got his powers already stolen)
Also, the dragons are basically a secret, only those who comes for the 100 years’ quest, are the only ones to whom the information is disclosed, they are sworn to secrecy as well.
But they mostly die (the ones who goes on this mission) only Gildarts came back alive, but couldn’t tell ‘em the deets cuz it’s confidential.
Most likely that stopped the flow of information and hence, here we are!
Also, zeref was kinda immortal, but he made monsters to kill him, his trump was END ( ie natsu revived from the dead), only he could kill him, especially since natsu was his reason and source behind dark magic, it sounds kinda logical, the one who borne the monster called “the black wizard”, could only END it! Makes total sense ( and believing that, Mavis also left defeating zeref to Natsu)
The 5 dragons probably fled from the ancient war among humans and dragons , so they were probably in hiding OR it could be that they were never involved in the war, hence Acnologia had no knowledge of their existence.
GOD this comment got HUGE!
Thanks for reading, whoever did take the trouble to!