Owari no Seraph was definitely one of the most hyped up anime this season, but it does have a reason to be like that. This is my own opinion, but I found this series very fun and exciting.
[Story - 7]
Now I admit the idea isn't... Creative. Boy seeking revenge for his family against vampires, sounds similar to Shingeki no Kyojin, no?(except it's titans) Hey, what can you do. As long as it's still enjoyable it's not that horrible. The thing that made this anime enjoyable was the anticipation of how things will unfold in the end. Will it go horribly or smoothly? That's the reason many enjoyed this series.
[Art - 8]
The art wasn't extravagant, but I believe it didn't need to be anything special. It was smooth and pleasing to the eye. Not much to say there.
[Sound - 9]
Now the opening was something I enjoyed A LOT. The opening itself gave the anime a huge hype, the song just makes you all pumped up and want to sing along!(Also can we just talk about the freaking Universal logo thing at the beginning of each episode?) Now for the rest of the anime, I believe, that the sound played quite a large role. It got you pumped up when something was about to happen and also made you tear up at times because of something horrible happening. This is what music in anime is supposed to do, pull on your heart strings. And so, I myself think that the sound in Owari no Seraph did indeed have that. Of course it wasn't so good as to give a 10, that's reserved for Clannad.
[Character - 9]
I loved the characters in this. They were all unique in their own way and I can't say I hated any of them (Except maybe Shinoa because gurl, know when to stop). They all had their views and I'm glad we got decent backstory on at least Yuu's friends. I'll expect to find out more from Guren next season because he's the one I'm interested in the most, and maybe we'll even get some backstory from the other generals as well.
[Enjoyment - 10]
Now I, for one, found this anime extremely enjoyable. Sure it's not perfect, it has it's flaws but those flaws didn't affect the enjoyment, which is good. Every week I was pumped up to watch the new episode and see what happens next, it made me cry and also happy and too excited than I should have been lol. Anticipation for the next episode is already a sign that the anime is going to be good.
[Overall - 9]
Now I would definitely suggest someone to watch this anime. If you like shounen/vampire anime then this definitely is for you. For me the first episode already got me, but if the first episode isn't convincing then watch the first three. The first three should be enough for you to decide whether to continue watching it or not.