The Seven Deadly Sins travel to a remote land in search of the phantom ingredient "sky fish." Meliodas and Hawk end up at a "Sky Palace" that exists above the clouds, where all the residents have wings. Meliodas is mistaken for a boy who committed a crime and is thrown in prison. Meanwhile, the residents are preparing a ceremony for defense against a ferocious beast that awakens once every 3,000 years. But the Six Knights of Black, a Demon Clan army, arrives and removes the seal on the beast in order to threaten the lives of the residents of Sky Palace. Meliodas and his allies meet the Six Knights of Black in battle.
Note: I had to watch the movie German-dubbed in the cinema after watching both seasons with German subs, so I wasn't able to fully enjoy the movie because the dub was not really nice in my opinion...
The movie looks to have been done so that also watchers who didn't watch the anime could enjoy it, but that makes it quite "flat" story-wise. There is nothing new and special for all who watched the two seasons, and there's no additional thrill or any unforeseeable plot twist. That's understandable but sad.
The story would definitely not fit for an OVA, but this movie has quite many
lengths. Mostly in the first half, nothing really happens and only the characters and the setting get explained a bit. The second half was nice as soon as the fights started. The storyline is a little bit random, involving "Sky Winged ones" and a demon fight almost not related to the TV series at all.
Also, it's not clear at which point of the anime story the movie is placed. It has to be at least after the middle of season 2 because of the involvement of all sins, but the overall setting was too peaceful to be set somewhen during season 2?
The same as in the anime series. Quite many additional landscape shots that were visually stunning but unnecessary storywise, but that's fine for a cinema movie.
Was also the same as in the anime series, I liked it very much. The ending song was also quite good.
The characters are the same main characters from the anime. There is no progress in characterization, and just some small explanations of the already known abilities of the Seven Deadly Sins. The only additional thing we get is a small hint at Elizabeth's abilities and strength (which has also somehow been teasered at the end of season 2 already). And a new special move for defeating enemies. That's okay, but nothing more.
The movie was fun, Hawk did very interesting and funny things and the fights were nice, too. Overall, the humor was the best thing of the movie aside from the visuals. The dialogues seemed fine as far as I could tell because of the problems I had with the dubbing. Sadly there was no additional fanservice.
I am not sure why this movie was made. For newbies to Seven Deadly Sins it gives more questions than answers (maybe they want to lure them into watching the rest?), and for all who have seen both seasons there is nothing new. It's fun, and the story was okay, nothing more. I gave the movie a 6,5/10 overall, which is a 7/10 here on MAL. (for better comparison: I gave season 1 a 9,5/10 and season 2 an 8,5/10)
If you like Seven Deadly Sins, you can watch the movie, but it's not really necessary. If you haven't seen the anime series yet, better watch it first.