Cryptid is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Robin, an ordinary high school student in South Korea. On his usual way home from school, an air raid siren blares across the city, and an unidentified ‘thing’ completely shatters Robin’s normal life. Robin gets caught up in a battle between the long-forgotten ‘Cryptids’ and the ‘Nameless Corps’ who protect humanity… Wait, this is scary!!!