The Night The World Went Dark by Jack Randall

When Jay Abbas and his friends accidentally summoned a demon from a fairytale, the sun refused to rise. They were forced to spend their days running, hiding, and plotting to send it back, and to undo all of the death and chaos that it had caused. However, the longer they were chased, the more likely death seemed. With time running out and their minds wearing thin, they unravel the mysteries of the island home, hoping at least one answer could save them from a dreadful fate.