Story
Pre-Timeskip
The story of magi starts off in the form of a story about a young Magi by the name of Aladdin who meets another human, Alibaba. Together the two kids decide to go on a journey going through some of the many dungeons which had started mysteriously appearing around the world, these dungeons were said to be full of riches as well as Djinn's, which would give the person who cleared the dungeon a household vessel within which to hold the Djinn in and to use its powers in battle, however there is an evil organisation by the name of Al Thamen who wish to recover all the Djinns for themselves so that they may have enough power to revive old god of Alma Torran, Ill Illah, thus Al thamen and many of the countries within the world start a war in an attempt to bring back Ill Illah and wreck havoc upon the entire world.
After this unsuccessful attempt, Aladdin himself gives us an insight on the old world of Alma Torran, where he and the many other humans who originally first came to the Planet within which they live on, this gives us an insight on the enormous Universe that the Magi verse contains and the vast amount of characters that came before, as well as setting up the premise for the current story arc and more importantly, the main villain to come. Thus after we hear about the story of Alma Torran and King Solomon, the verse has a time-skip wherein many of the characters have boosts in power and age.
Post Time-Skip
After the Timeskip, the verse as a whole takes a much darker turn, especially within some main characters such as Sinbad, we are introduced a more politically driven and darker but on a smaller scale motives from the characters. Beyond chapter 324 the verse takes a much different turn once again, this time adhering to becoming Saint Seiya 2.0, currently the story arc is ever changing with twists and turns, Magi in all is a very fantastic Manga to read, never boring the reader and always bringing something new to the table, currently the manga is in its final arc, expecting to finish within the next 50 or so chapters.
Power
Magi may honestly have one of the biggest discrepancies for the power between their tiers, Their fodder and low tiers are at the very least still Superhuman and easily Wall level, any Fanalis is capable of this. Their High Tiers such as Masrur are around City level, Top tiers tiers within the verse are at the high ends of city level with characters such as Pre-Timeskip Judar being able to decimate a part of an island with ease, The god tiers is where the power in the verse takes a ridiculous leap, The current god tiers of the verse stand at around Low Multiverse level, characters who exist outside of space-time, have a whole plethora of hax (Sinbad was able to rewrite the minds of an entire planet, Aladdin can literally manipulate the very laws of physics with a flick of his finger and Ugo can change the power of Universal+ beings who in comparison to him are like comparing an author to his fictional characters), all in all Magi is slowly but surely becoming one of the strongest Manga series out there, with more and more characters scaling to the Universal feats, the series is going to make a name for their power, however now that it is in its final arc, there is much doubt as to whether they will get more powerful or not.