Ishura was a based on a light novel series written by Keiso which started gaining popularity for from self publishing sites like Kakuyomu and Shōsetsuka ni Narō. This is an isekai fantasy battle royale type of story where you have several characters running around in the show connected by interrelated series of events that led them to one another building up to the great clash.
The demon king is dead but nobody knows the hero that vanquished him. However, the world still had "Shuras", individuals of great fighting prowess worthy to claim the new demon king title. And these Shuras are motivated by their own self interests which vary from ruling nations, pick fights for the heck of it, or prestige. Because the identity of the real hero that has slain the demon king is unknown, almost every Shura is led to want stake their claim on the title as the "True Hero" leading the a grand tournament.
SPOILER
The entire season is spent building up the hype leading to the grand tournament that decides who the "True Hero". We're introduced to the Shuras like they are the main characters with their own back stories. This show has a lot of them and since some episodes are entirely devoted into building them up with lengthy screen time, it's not hard to get attached to some of their motivations.
But make no mistake about getting attached to each Shura as this show tends to twists some plots and kills off even the most powerful characters on the series. I mentioned about the isekai part of the show, well some of the Shuras came from another world but not the standard modern world we're familiar with, it's hinted that there are alternate realities existing but for reasons unclear.
Almost everyone seems to have like an overpowered ability that makes them worth of the hero title or be the next demon king. Some of their strengths are from the magic tools gathered, their own skills trained over the years or abilities they are simply born with.
It's hard to commit to a single candidate as a victor because more characters are introduced every few episodes with their overpowered abilities one upping the other characters in some way. But this is what makes the show being suspenseful as you can't really expect who's going to survive to the season finale. The battle royale has started even before the formal Hero's tournament.
Ishura does not disappoint when it comes to the fight scenes and has made use of 3D elements on top of the 2D animation. It's visually engaging to see characters clash which is complemented the story.
Thanks for your time.
