 If you liked
Owari no Seraph
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 ...then you might like
Enen no Shouboutai
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Both include brothers fighting in fantasy world using different powers and weapons. Brothers are seperated one for "good" guys and one for "bad" guys and in both series there is seek for reunition and they don't know much about the surrounding world and what mysteries they are fighting against. In owari no seraph they are brothers only formally.
Pretty standard battle shounen. Both have a protagonist group with similar relationships between characters and similar outfit designs as well. The main characters in both have a personal connection with a character from the 'evil' team. There is a male character in both who has short pink hair.
Both are shonens which take place in postapocaliptic world. Main characters join the organisation to fight the monsters which started the apocalypse and killed their family. The protagonists fight the evil organisation in which one of their relatives is a member. Both of the stories has typical shonen stamps, like the demon thing inside main character and their goal to destroy all evil.