Fairy Tail is the story of Lucy Heartfilia and Natsu Dragneel of the Fairy Tail guild. Lucy left home in order to become part of a mage's guild and after running into some trouble she meets Natsu Dragneel whom invites her to Fairy Tail which she happily joins. In this world filled with mages and guilds, there is constant competition. However, like in everything there is a dark side to the coin and there are also plenty dark mages out there. Misteriously dissappearing dragons, Zeref the death mage, Acnologia the black dragon king, dragon slayers, demons are some of the things besides the ordinary rouge mage which they have to worry about.
The series has been somewhat inconsistent and slow in its power progression (unlike with its fanservice...). Series started around large building level and after hundreds of chapters it was still only town level. During the early, generally agreed to be best arcs of the series the verses power is around multi block to town level. Before they reach their first timeskip they still only reach about town+, with potentially much stronger characters introduced. Before they reach their second timeskip they end around city to mountain level. Currently their top tiers reach around island level power and country level hype (which the hype regarding it has been pretty consistent so far, so hope Mashima doesnt nerf it with his inconsistent writting again). The speed of the verse started off pretty low with only a few debatably consistent supersonic showings, but eventually reached hypersonic+ and is currently sitting between the high hypersonic+ to massively hypersonic range. The verse has decent hax being somewhere between One Piece to Naruto level in their department, however that recently has gotten a nerf by making the "No Limits Fallacy" on their verses magic all too clear by having E.N.D. and even amped Neinheart being able to walk through the magic of top tiers like Brandish and Dimaria due to their difference in power. Thanks to nigh god tier Irene and her Deus Sema meteor they have now reached sub-relativistic speeds and at least country level power, finally being able to pose a threat to Naruto and Bleach charas that arent top to God tier and to all of One Piece.
Characters are listed by their Guild/Factions
Fairy Tail Guild
Mermaid Heel Guild
Celestial Soul King