I believe that in most of the arcs of the manga there is a certain concept that is shown by the plot, characters, style of the story, or just frequently used (Even some concepts that the protagonists must overcome). What concepts do you think best describes each arcs?
Erza returns from her job and she starts taking over, she then asks Natsu and Gray to team up with her, to everyone's surprise this was a big change for them. The Dark Guild Eisenwald stole Lullaby in order to gain back their rights and hopefully things will change.
Galuna Island: Rivalry
When Natsu, Happy and Lucy go on an illegible job at Galuna Island, Gray goes to take them back but was dragged along with them, what they wouldn't realize is the secret they would find on the island, Gray's fellow pupal Lyon was attempting to bring back Deliora to prove his strength an surpass his teacher/rival Ur.
Never had the current generation of Fairy Tail experience a war with another guild until the guild Phantom Lord started attacking them. This was the first time that they had been challenge and pushed to their limits against an enemy. This was all started because a private family discord between Lucy and her father.
For Loke's crime for letting her Celestial Wizard Karen Lilica die, he was forever banished from the Celestial Spirit World. He was also bound by the guilt of "killing" her and suffered for 3 years, until he met Lucy, because of that he slowly began to believe in Celestial Wizards again before he died, unless Lucy attempts to save him. She would risk everything to save her friend.
Tower of Heaven: Freedom
When Team Natsu was taking vacation, old friends of Erza's have returned to take her back to the Tower of Heaven where they were slaves in their youth, Jellal, another old friend of hers was like the leader and was fighting for their freedom, when Erza took up the mantle, Jellal came to be controlled by the 'spirit of Zeref' and desired 'True Freedom', he let Erza go, she may had been freed but she was imprisoned by her guilt of leave her friends behind, she was freed from her burdens as Natsu beat Jellal but was intending to sacrifice herself to save everyone, Jellal freed from the 'spirit' took Erza's place. Her nightmare was over and her friends were freed as well.
Fairy Tail Battle Festival: Family
The S-class Mage Laxus has had a strong dislike of his grandfather because of his father's exile from Fairy Tail, and now past the tipping point Laxus and the Thunder God Tribe decided to start a coup called the "Fairy Tail Battle Festival". This was also to test Gajeel's and Juvia's acceptance into the Fairy Tail Family. What Laxus will soon realize is that the guild is not something to be inherited by blood, everyone in Fairy Tail is family.
Oracion Seis: Chaos
As the Dark Guilds organized, so to do the Balam Alliance, and Oración Seis desired a Ancient Magic, as the Light Team was charged to stop them, during most of their fights there where enemies that would just disregard the rules of their magic, Oracion Seis's goal is to bring the world into chaos, as Zero appeared, he had no regards to their goals and didn't discern friend from foe, he just wanted to destroy. And as the new Magic Council appeared to take Jellal away, and the Light Team was helpless to stop them. This is the first time Fairy Tail faced an enemy truly powerful.
The Kingdom of Edolas who for years have been the key stone of opulence and excess as they stole magical energy from Earthland to sustain their dying supply of magic, Natsu and the others have attempted to go into Edolas and wished to save their guild, the Exceed who have been for a long time have been mistreated by humans have tricked them in order to desire a little respect. As the Kingdom planned a plan to gain infinite amount of magic, they would sacrifice anything to get it. They view that Magic is more valuable than anything else But Natsu and others view life is more important. This is a battle for what is most valuable.
Tenrou Island: Fear
During the S-Class Mage Promotion Trial on Tenrou Island, Natsu was so eager to face legendary Gildarts, blinded by his over-confidence, Natsu for the first time in his life understood the true meaning of FEAR, As Grimoire Heart attacked the island, Natsu again frozen with fear tried to overcome it and did, to all the Fairy Tail Mages horror came to understand that Zeref was alive on the island. During the final battle with Hades, Team Natsu thought they had him on the ropes but have once more been paralyzed by fear. And when they realized they were together, they have overcome their fear.
Grand Magic Games/Eclipse: Rebirth/Despair
After 7 years of being trapped on Tenrou Island, Fairy Tail have decide to partake in the Grand Magic Games to gain back their title of 1# Guild in Fiore, they first have to prove themselves and overcome many fearsome Guilds, this will Fairy Tail's Rebirth.
While in the shadows a knight seeks to create a device for the sake of a certain plan and requires a certain girl. While an omen of ill fate was about to befall the people of the entire world. For the earth will come to know Despair.
Sun Village: Nostalgia
After the Grand Magic Games, Fairy Tail was requested to take on a job to unfreeze a village, to Gray he is experiencing some nostalgic feelings, seeing frozen Giants and seeing Deliora, Treasure Hunters in possession of Liquid Moon Drip, Ice magic familiar to Gray, Natsu hearing a voice he remembers, And Flare who had come home to the village that raised her. As Succubus Eye Mage Doriate uses his magic to bring people back to "days of old", Gray having been turned back into a kid starts to freak out as he remembers his childhood drama's as he fights Doriate. And lastly, the Eternal Flame turned out to be Atlas Flame as he remembered Natsu and says "It's been 400 years". And Walrod Cken reveals that he was once a FT Mage, and that when Natsu's group came to him was a nostalgic feeling.
When the Magic Council is attacked by the Nine Demon Gate's Jackal, most of the people except for Doranbolt are dead, he witnessed the death of his teacher and best friend and escaped and is now out for a quest of revenge. Later After the Nine Demon Gate's Tempesta attacks 8-Island restaurant, Laxus Dreyar, the Raijinshuu and Yajima bearly managed to escape with their lives, Freed Justine asked if the town was ok, but Makarov Dreyar lied to spare him the pain of know that hundreds of people died. Then Natsu out of rage states a war against Tartarus. Elfman is choking Lisanna and is begging Sayla to stop but is asked if he is willing to sell his soul. Now Fairy Tail will now take the Pain and Suffering and turn it to fighting spirit, but how long will that last?
(Will Change/Update when more information comes in.)
Rule: Please do not make Nakama jokes!!!
Note, Friendship is common in all the arcs, so please don't state that.