Fairy Tail's final season presented Lucy and Natsu with the challenge of bringing the Fairy Tail guild back together, but they are quickly finding out that their friends are in a much different situation than when they last met.
Gray Fullbuster has been especially mysterious as now the character has made a villainous turn, joining the black magic cult, Avatar.
Earlier in the series, Juvia had explained how she and Gray had been living together in an abandoned village. They had spent most of their time with one another, but suddenly Gray left Juvia alone without warning for six months. It turns out that he's joined Avatar, a cult worshipping Zeref.
Avatar worships Zeref as he will bring about the "purification" of the world, and the cult is full of seemingly powerful mages. Gray was revealed to be one of these and it's leading to some distrust among the other members. They question his loyalty, as he doesn't revere Zeref like the rest of them, but then Gray reveals why he's there in the first place.
Gray's family has been killed by a demon from the book of Zeref, and Gray's master and daughter had died due to Zeref as well, but Gray says Ultear isn't dead and clears up his villainous motivation. He's in the cult for the Book of E.N.D., and will do whatever it takes to either get the book or defeat "E.N.D."
He's been consumed by revenge, and this is a much different Gray than fans are used to seeing. His dark magic power has completely changed him, but hopefully he's not unreachable.
Fairy Tail was originally created by Hiro Mashima for Kodansha's Weekly Shonen Magazine, running from 2006 to 2017 and selling over 60 million copies. The series is set in a fantasy world full of magic following Natsu Dragneel, a fire breathing wizard with the powers of a dragon who is in search of his missing foster father, the dragon Igneel. As he and his wizarding guild Fairy Tail get into adventures, Natsu always tries to find a way to succeed. The series was later adapted into an anime by A-1 Pictures, Dentsu Inc., and Satelight in 2009 and ended its first run in 2013. A second season ran from 2014 to 2016, and the third season serves as the final one.
If you're itching for more Fairy Tail, Fairy Tail: 100 Years Quest is an official manga sequel to the original series featuring original storyboards provided by Hiro Mashima and illustrated by Atsuo Ueda. The series picks up right where the original manga ends as Natsu, Lucy, and the others embark on the "100 Years Quest" that no mage has ever completed before.