This anime series is called Owari no seraph or Seraph of the end. 

I love the setting and characters. From this series, I was inspired to make Apollo, Artemis, Blazey and creepster. 

Yuu inspired me to make Artemis and Blazey while Mikaela(the blond colored boy) inspired me to make Apollo and Creepster.

This series is called Magical Girl Rising Project. This seems to be a girly series however it takes a very dark turn when it goes danganronpa. The funny thing about this series is that it looks like a mixture of Dangan Ronpa and Puella Magi Madoka Magica. Even the good(actually bad guys look like they had a baby together.

However I'm not here to waste your time.

These two kids inspired the creation of Scott and Angela(named by FallMistress ) or the twins with black eyes and outfits. 

The one child at the top, Yunael the right winged angel, inspired to make Angela. The left winged angel, Yuna, was inspired to make Scott. They also have the wings on the same sides as there inspiration.

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Extra: I have said inspired a lot. It does exist and it doesn't mean it's copying. If you haven't seen, many ocs have been inspired by other people. The reason they say inspired is because millions of people use other people to boost their hopes that one day that can make things that their favorite people do. However, if it's copying, it means they trace your art or use the exact designs you make. If the colors are changed, it's half ok.

Many people get inspired to make relatable characters. I won't argue with what you guys think but this is what I think, even though I suck at explaining it.